Compression resistant implants including an oxysterol and methods of use

ABSTRACT

Provided is a compression resistant implant configured to fit at or near a bone defect to promote bone growth, the compression resistant implant comprising porous ceramic particles in a biodegradable polymer, and an oxysterol disposed in or on the compression resistant implant. Methods of making and use are further provided.

BACKGROUND

Biologics are commonly employed to promote bone growth in medicalapplications including fracture healing and surgical management ofspinal disorders. Spine fusion is often performed by orthopedic surgeonsand neurosurgeons alike to address degenerative disc disease andarthritis affecting the lumbar and cervical spine, to correctdeformities caused by scoliosis, and to repair instability due tospondylolisthesis. Additionally, the techniques of spinal fusion may beapplied to treat arm or leg pain caused by compressed spinal nerves.Historically, autogenous bone grafting, commonly taken from the iliaccrest of the patient, has been used to augment fusion between vertebrallevels.

One protein that is osteogenic and commonly used to promote spine fusionis recombinant human bone morphogenetic protein-2 (rhBMP-2). Smallmolecules have also been use to induce bone growth. Oxysterols form alarge family of oxygenated derivatives of cholesterol that are presentin the circulation, and in human and animal tissues. Oxysterols havebeen found to be present in atherosclerotic lesions and play a role invarious physiologic processes, such as cellular differentiation,inflammation, apoptosis, and steroid production. Some naturallyoccurring oxysterols have robust osteogenic properties and can be usedto grow bone. The most potent osteogenic naturally occurring oxysterol,20(S)-hydroxycholesterol, is both osteogenic and anti-adipogenic whenapplied to multipotent mesenchymal cells capable of differentiating intoosteoblasts and adipocytes.

One such oxysterol is Oxy133 or (3S,5S,6S,8R,9S,10R, 13S, 14S,17S)17-((S)-2-hydroxyoctan-2-yl)-10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthrene-3,6-diol, whichexhibits the following structures:

A variety of materials have been suggested for the treatment of bonedefects. In addition to traditional bone grafting, a number of syntheticbone graft substitutes have been used or explored, including severalmatrix materials.

To conduct bone growth effectively, implant materials derive benefitfrom the presence of substantial scaffolding material such asbiocompatible ceramics or other mineral scaffolds. Such mineralmaterials are generally hard, and/or brittle substances. Theincorporation of substantial levels of mineral particles into matrixmaterials, particularly if the mineral particles are granules or otherrelatively large particles, may be difficult because the large particlesof hard minerals tend to disrupt the matrix mass such that it is readilybroken or eroded away, and lacks cohesiveness desired for handling priorto implant and for persistence after implant. This may present problemsin achieving effective bone growth into and through the desired implantvolume, due to migration or separation of the scaffolding particulates.

Therefore, there exist needs for improved compression-resistant implantswhich not only have high levels of incorporated, mineral particles, butalso maintain the desired combination of compression strength andcohesiveness. Additionally, there is a need to providecompression-resistant implants which incorporate an osteogenic agent,such as an oxysterol in it. Furthermore, there is also a need for acompression resistant implant having adhesive properties to bind toother medical implants such as screws, rods, plates, and interbodydevices comprising bone, allograft, autograft, synthetic materialsand/or PEEK.

SUMMARY

Compression resistant implants and methods of making and using thoseimplants are provided. The compression resistant implants can be formedto fit easily within a bone defect. The compression resistant implantshave mineral particles incorporated within them and also maintain thedesired combination of compressive strength and cohesiveness.Additionally, provided are compression resistant implants whichincorporate an osteogenic agent, such as an oxysterol in it.

In one aspect, the present application is directed to an implantableosteogenic medical material comprising a compression resistant andcohesive implant that includes a combination of a biodegradable polymer,mineral particles and an active agent comprising an oxysterol. Inanother aspect, the present application is directed to a compressionresistant implant having adhesive properties to bind to other medicalimplants such as screws, rods, plates, and interbody devices comprisingbone, allograft, autograft, synthetic materials and/or PEEK.

In some embodiments, the compression resistant implant can be a robustimplant that can have a high mineral content or allograft content, stillbind and be cohesive.

In some embodiments, provided is a compression resistant implant havingan active agent comprising the structure:

or a pharmaceutically acceptable salt, hydrate or solvate thereof,wherein R1 comprises an aliphatic or cyclic substituent having at leastone carbon atom. In some embodiments, the active agent is a sterolcomprising Oxy133.

In some embodiments, provided is a compression resistant implantconfigured to fit at or near a bone defect to promote bone growth, thecompression resistant implant comprising porous ceramic particles in anamount of about 30 wt % to about 99.5 wt % based on a total weight ofthe implant in a biodegradable polymer in an amount of about 0.11 wt %to about 20 wt % based on the total weight of the implant, and anoxysterol disposed in or on the compression resistant implant.

In some embodiments, provided is a method of treating a bone defect, themethod comprising implanting a compression resistant implant at or nearthe bone defect to promote bone growth, the compression resistantimplant comprising porous ceramic particles in an amount of about 30 wt% to about 99.5 wt % based on a total weight of the implant in abiodegradable polymer in an amount of about 0.1 wt % to about 20 wt %based on the total weight of the implant, and an oxysterol disposed inor on the compression resistant implant so as to treat the bone defect.

In some embodiments, provided is a method for making a compressionresistant implant, the method comprising (i) adding porous ceramicparticles in an amount of about 30 wt % to about 99.5 wt % based on atotal weight of the implant to a biodegradable polymer in an amount ofabout 0.1 wt % to about 20 wt % based on the total weight of the implantto form a mixture and adding an oxysterol to the mixture to form thecompression resistant implant; (ii) adding an oxysterol to porousceramic particles, the porous ceramic particles being in an amount ofabout 30 wt % to about 99.5 wt % based on a total weight of the implantto form a mixture and adding a biodegradable polymer in an amount ofabout 0.1 wt % to about 20 wt % based on the total weight of the implantto form the compression resistant implant; or (iii) adding an oxysterolto a biodegradable polymer, the biodegradable polymer being in an amountof about 0.1 wt % to about 20 wt % based on the total weight of theimplant to form a mixture and adding porous ceramic particles to themixture to form the implant, the porous ceramic particles being in anamount of about 30 wt % to about 99.5 wt % based on a total weight ofthe implant.

Additional features and advantages of various embodiments will be setforth in part in the description that follows, and in part will beapparent from the description, or may be learned by practice of variousembodiments. The objectives and other advantages of various embodimentswill be realized and attained by means of the elements and combinationsparticularly pointed out in the description and appended claims.

BRIEF DESCRIPTION OF THE FIGURES

In part, other aspects, features, benefits and advantages of theembodiments will be apparent with regard to the following description,appended claims and accompanying drawings where:

FIG. 1 illustrates powder components of a malleable implant which havebeen wetted by a fluid but have not yet been mixed. The cohesive massincludes a biodegradable polymer such as collagen, mineral particlessuch as ceramic, and an active agent such as an oxysterol;

FIG. 2 illustrates a malleable implant after it has been wetted by afluid. The malleable implant includes a biodegradable polymer such ascollagen, mineral particles such as ceramic, and an active agent such asan oxysterol. The malleable implant is moldable into a shape to fit abone defect. As shown in FIG. 2, the malleable implant is wetted withblood or bone marrow aspirate and formed into a cylindrical shape;

FIG. 3 illustrates a malleable implant after it has been wetted by afluid. The malleable implant includes a biodegradable polymer such ascollagen, mineral particles such as ceramic, and an active agent such asan oxysterol. The malleable implant is moldable into a shape to fit abone defect. As shown in FIG. 3, the malleable implant is wetted withblood or bone marrow aspirate and formed into a spherical shape;

FIG. 4 illustrates a malleable implant after it has been wetted by afluid. The malleable implant includes a biodegradable polymer such ascollagen, mineral particles such as ceramic, and an active agent such asan oxysterol. The malleable implant is moldable into a shape to fit abone defect. As shown in FIG. 4, the malleable implant is wetted withwater or saline and formed into a cylindrical shape;

FIG. 5 illustrates a malleable implant after it has been wetted by afluid. The malleable implant includes a biodegradable polymer such ascollagen, mineral particles such as ceramic, and an active agent such asan oxysterol. The malleable implant is moldable into a shape to fit abone defect. As shown in FIG. 5, the malleable implant is wetted withwater or saline and formed into a spherical shape;

FIG. 6 illustrates uses of a formulation of malleable implants having 20mg of Oxy133 on each side of the implant, in accordance with themalleable implants described herein. As shown in FIG. 6, implantation ofthe implants in the posterolateral space yielded spinal fusion in a rattwo-level spine model. Bone growth in rat test subjects can be seenafter 4 and 8 weeks post-implantation, and fusion was confirmed bymanual palpation of the spine segments at 8 weeks; and

FIG. 7 illustrates uses of a formulation of malleable implants having125 mg of Oxy133 on each side of the implant, in accordance with themalleable implants described herein. As shown in FIG. 7, implantation ofthe implants in the posterolateral space yielded spinal fusion in a rattwo-level spine model. Bone growth in rat test subjects can be seenafter 4 and 8 weeks post-implantation, and fusion was confirmed bymanual palpation of the spine segments at 8 weeks.

It is to be understood that the figures may not be to scale. Further,the relation between objects in a figure may not be to scale, and may infact have a reverse relationship as to size. The figures are intended tobring understanding and clarity to the structure of each object shown,and thus, some features may be exaggerated in order to illustrate aspecific feature of a structure.

DETAILED DESCRIPTION

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities of ingredients,percentages or proportions of materials, reaction conditions, and othernumerical values used in the specification and claims, are to beunderstood as being modified in all instances by the term “about.”Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired propertiessought to be obtained by the present application. At the very least, andnot as an attempt to limit the application of the doctrine ofequivalents to the scope of the claims, each numerical parameter shouldat least be construed in light of the number of reported significantdigits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the present application are approximations, thenumerical values set forth in the specific examples are reported asprecisely as possible. Any numerical value, however, inherently containscertain errors necessarily resulting from the standard deviation foundin their respective testing measurements. Moreover, all ranges disclosedherein are to be understood to encompass any and all sub ranges subsumedtherein. For example, a range of “1 to 10” includes any and all subranges between (and including) the minimum value of 1 and the maximumvalue of 10, that is, any and all sub ranges having a minimum value ofequal to or greater than 1 and a maximum value of equal to or less than10, e.g., 5.5 to 10.

Definitions

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the,” include plural referents unlessexpressly and unequivocally limited to one referent. Thus, for example,reference to “an implant” includes one, two, three or more implants.

The term “bioactive agent” as used herein is generally meant to refer toany substance that alters the physiology of a patient. The term“bioactive agent” may be used interchangeably herein with the terms“therapeutic agent,” “therapeutically effective amount,” and “activepharmaceutical ingredient”, “API” or “drug”.

The term “biodegradable” includes compounds or components that willdegrade over time by the action of enzymes, by hydrolytic action and/orby other similar mechanisms in the human body. In various embodiments,“biodegradable” includes that components can break down or degradewithin the body to non-toxic components as cells (e.g., bone cells)infiltrate the components and allow repair of the defect. By“bioerodible” it is meant that the compounds or components will erode ordegrade over time due, at least in part, to contact with substancesfound in the surrounding tissue, fluids or by cellular action. By“bioabsorbable” it is meant that the compounds or components will bebroken down and absorbed within the human body, for example, by a cellor tissue. “Biocompatible” means that the compounds or components willnot cause substantial tissue irritation or necrosis at the target tissuesite and/or will not be carcinogenic.

The term “alkyl” as used herein, refers to a saturated or unsaturated,branched, straight-chain or cyclic monovalent hydrocarbon radicalderived by the removal of one hydrogen atom from a single carbon atom ofa parent alkane, alkene or alkyne. Typical alkyl groups include, but arenot limited to, methyl; ethyls such as ethanyl, ethenyl, ethynyl;propyls such as propan-1-yl, propan-2-yl, cyclopropan-1-yl,prop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl, cycloprop-1-en-1-yl;cycloprop-2-en-1-yl, prop-1-yn-1-yl, prop-2-yn-1-yl, etc.; butyls suchas butan-1-yl, butan-2-yl, 2-methyl-propan-1-yl, 2-methyl-propan-2-yl,cyclobutan-1-yl, but-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl,but-2-en-1-yl, but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl,cyclobut-1-en-1-yl, cyclobut-1-en-3-yl, cyclobuta-1,3-dien-1-yl,but-1-yn-1-yl, but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the like. Wherespecific levels of saturation are intended, the nomenclature “alkenyl”and/or “alkynyl” is used, as defined below. In some embodiments, thealkyl groups are (C1-C40) alkyl. In some embodiments, the alkyl groupsare (C1-C6) alkyl.

The term “alkanyl” as used herein refers to a saturated branched,straight-chain or cyclic alkyl radical derived by the removal of onehydrogen atom from a single carbon atom of a parent alkane. Typicalalkanyl groups include, but are not limited to, methanyl; ethenyl;propanyls such as propan-1-yl, propan-2-yl(isopropyl), cyclopropan-1-yl,etc.; butyanyls such as butan-1-yl, butan-2-yl (sec-butyl),2-methyl-propan-1-yl (isobutyl), 2-methyl-propan-2-yl (t-butyl),cyclobutan-1-yl, etc.; and the like. In some embodiments, the alkanylgroups are (C1-C40) alkanyl. In some embodiments, the alkanyl groups are(C1-C6) alkanyl.

The term “alkenyl” as used herein refers to an unsaturated branched,straight-chain or cyclic alkyl radical having at least one carbon-carbondouble bond derived by the removal of one hydrogen atom from a singlecarbon atom of a parent alkene. The radical may be in either the cis ortrans conformation about the double bond(s). Typical alkenyl groupsinclude, but are not limited to, ethenyl; propenyls such asprop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl, prop-2-en-2-yl,cycloprop-1-en-1-yl; cycloprop-2-en-1-yl; butenyls such asbut-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl, but-2-en-1-yl,but-2-en-1-yl, but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl,cyclobut-1-en-1-yl, cyclobut-1-en-3-yl, cyclobuta-1,3-dien-1-yl, etc.;and the like. In some embodiments, the alkenyl group is (C2-C40)alkenyl. In some embodiments, the alkenyl group is (C2-C6) alkenyl.

The term “alkynyl” as used herein refers to an unsaturated branched,straight-chain or cyclic alkyl radical having at least one carbon-carbontriple bond derived by the removal of one hydrogen atom from a singlecarbon atom of a parent alkyne. Typical alkynyl groups include, but arenot limited to, ethynyl; propynyls such as prop-1-yn-1-yl,prop-2-yn-1-yl, etc.; butynyls such as but-1-yn-1-yl, but-3-yn-1-yl,etc.; and the like. In some embodiments, the alkynyl group is (C2-C40)alkynyl. In some embodiments, the alkynyl group is (C2-C6) alkynyl.

The term “alkyldiyl” as used herein refers to a saturated orunsaturated, branched, straight-chain or cyclic divalent hydrocarbonradical derived by the removal of one hydrogen atom from each of twodifferent carbon atoms of a parent alkane, alkene or alkyne, or by theremoval of two hydrogen atoms from a single carbon atom of a parentalkane, alkene or alkyne.

The two monovalent radical centers or each valency of the divalentradical center can form bonds with the same or different atoms. Typicalalkyldiyls include, but are not limited to methandiyl; ethyldiyls suchas ethan-1,1-diyl, ethan-1,2-diyl, ethen-1,1-diyl, ethen-1,2-diyl;propyldiyls such as propan-1,1-diyl, propan-1,2-diyl, propan-2,2-diyl,propan-1,3-diyl, cyclopropan-1,1-diyl, cyclopropan-1,2-diyl,prop-1-en-1,1-diyl, prop-1-en-1,2-diyl, prop-2-en-1,2-diyl,prop-1-en-1,3-diyl cycloprop-1-en-1,2-diyl, cycloprop-2-en-1,2-diyl,cycloprop-2-en-1,1-diyl, prop-1-yn-1,3-diyl, etc.; butyldiyls such as,butan-1,1-diyl, butan-1,2-diyl, butan-1,3-diyl, butan-1,4-diyl,butan-2,2-diyl, 2-methyl-propan-1,1-diyl, 2-methyl-propan-1,2-diyl,cyclobutan-1,1-diyl; cyclobutan-1,2-diyl, cyclobutan-1,3-diyl,but-1-en-1,1-diyl, but-1-en-1,2-diyl, but-1-en-1,3-diyl,but-1-en-1,4-diyl, 2-methyl-prop-1-en-1,1-diyl,2-methanylidene-propan-1,1-diyl, buta-1,3-dien-1,1-diyl,buta-1,3-dien-1,3-diyl, cyclobut-1-en-1,2-diyl, cyclobut-1-en-1,3-diyl,cyclobut-2-en-1,2-diyl, cyclobuta-1,3-dien-1,2-diyl,cyclobuta-1,3-dien-1,3-diyl, but-1-yn-1,3-diyl, but-1-yn-1,4-diyl,buta-1,3-diyn-1,4-diyl, etc.; and the like. Where specific levels ofsaturation are intended, the nomenclature alkanyldiyl, alkenyldiyland/or alkynyldiyl is used. In some embodiments, the alkyldiyl group is(C1-C40) alkyldiyl. In some embodiments, the alkyldiyl group is (C1-C6)alkyldiyl. Also contemplated are saturated acyclic alkanyldiyl radicalsin which the radical centers are at the terminal carbons, e.g.,methandiyl (methano); ethan-1,2-diyl(ethano); propan-1,3-diyl(propano);butan-1,4-diyl(butano); and the like (also referred to as alkylenos,defined infra).

The term “alkyleno” as used herein refers to a straight-chain alkyldiylradical having two terminal monovalent radical centers derived by theremoval of one hydrogen atom from each of the two terminal carbon atomsof straight-chain parent alkane, alkene or alkyne. Typical alkylenogroups include, but are not limited to, methano; ethylenos such asethano, etheno, ethyno; propylenos such as propano, prop[1]eno,propa[1,2]dieno, prop[1]yno, etc.; butylenos such as butano, but[1]eno,but[2]eno, buta[1,3]dieno, but[1]yno, but[2]yno, but[1,3]diyno, etc.;and the like. Where specific levels of saturation are intended, thenomenclature alkano, alkeno and/or alkyno is used. In some embodiments,the alkyleno group is (C1-C40) alkyleno. In some embodiments, thealkyleno group is (C1-C6) alkyleno.

The terms “heteroalkyl,” “heteroalkanyl,” “heteroalkenyl,”“heteroalkanyl,” “heteroalkyldiyl” and “heteroalkyleno” as used hereinrefer to alkyl, alkanyl, alkenyl, alkynyl, alkyldiyl and alkylenoradicals, respectively, in which one or more of the carbon atoms areeach independently replaced with the same or different heteroatomicgroups. Typical heteroatomic groups which can be included in theseradicals include, but are not limited to, —O—, —S—, —O—O—, —S—S—, —O—S—,—NR′, ═N—N═, —N═N—, —N(O)N—, —N═N—NR′—, —PH—, —P(O)2—, —O—P(O)2—, —SH2—,—S(O)2—, —SnH2— or the like, where each R′ is independently hydrogen,alkyl, alkanyl, alkenyl, alkynyl, aryl, arylaryl, arylalkyl, heteroaryl,heteroarylalkyl or heteroaryl-heteroaryl as defined herein.

The term “aryl” as used herein refers to a monovalent aromatichydrocarbon radical derived by the removal of one hydrogen atom from asingle carbon atom of a parent aromatic ring system. Typical aryl groupsinclude, but are not limited to, radicals derived from aceanthrylene,acenaphthylene, acephenanthrylene, anthracene, azulene, benzene,chrysene, coronene, fluoranthene, fluorene, hexacene, hexaphene,hexylene, as-indacene, s-indacene, indane, indene, naphthalene,octacene, octaphene, octalene, ovalene, penta-2,4-diene, pentacene,pentalene, pentaphene, perylene, phenalene, phenanthrene, picene,pleiadene, pyrene, pyranthrene, rubicene, triphenylene, trinaphthalene,and the like. In some embodiments, the aryl group is (C5-C14) aryl or a(C5-C10) aryl. Some preferred aryls are phenyl and naphthyl.

The term “aryldiyl” as used herein refers to a divalent aromatichydrocarbon radical derived by the removal of one hydrogen atom fromeach of two different carbon atoms of a parent aromatic ring system orby the removal of two hydrogen atoms from a single carbon atom of aparent aromatic ring system. The two monovalent radical centers or eachvalency of the divalent center can form bonds with the same or differentatom(s). Typical aryldiyl groups include, but are not limited to,divalent radicals derived from aceanthrylene, acenaphthylene,acephenanthrylene, anthracene, azulene, benzene, chrysene, coronene,fluoranthene, fluorine, hexacene, hexaphene, hexylene, as-indacene,s-indacene, indane, indene, naphthalene, octacene, octaphene, octalene,ovalene, penta-2,4-diene, pentacene, pentalene, pentaphene, perylene,phenalene, phenanthrene, picene, pleiadene, pyrene, pyranthrene,rubicene, triphenylene, trinaphthalene, and the like. In someembodiments, the aryldiyl group is (C5-C14) aryldiyl or (C5-C10)aryldiyl. For example, some preferred aryldiyl groups are divalentradicals derived from benzene and naphthalene, especiallyphena-1,4-diyl, naphtha-2,6-diyl and naphtha-2,7-diyl.

The term “arydeno” as used herein refers to a divalent bridge radicalhaving two adjacent monovalent radical centers derived by the removal ofone hydrogen atom from each of two adjacent carbon atoms of a parentaromatic ring system. Attaching an aryleno bridge radical, e.g. benzeno,to a parent aromatic ring system, e.g. benzene, results in a fusedaromatic ring system, e.g. naphthalene. The bridge is assumed to havethe maximum number of non-cumulative double bonds consistent with itsattachment to the resultant fused ring system. In order to avoiddouble-counting carbon atoms, when an aryleno substituent is formed bytaking together two adjacent substituents on a structure that includesalternative substituents, the carbon atoms of the aryleno bridge replacethe bridging carbon atoms of the structure. As an example, consider thefollowing structure:

wherein R¹, when taken alone is hydrogen, or when taken together with R²is (C5-C14) aryleno; and R², when taken alone is hydrogen, or when takentogether with R¹ is (C5-C14) aryleno.

When R¹ and R² are each hydrogen, the resultant compound is benzene.When R¹ taken together with R² is C6 aryleno (benzeno), the resultantcompound is naphthalene. When R¹ taken together with R² is C10 aryleno(naphthaleno), the resultant compound is anthracene or phenanthrene.Typical aryleno groups include, but are not limited to, aceanthryleno,acenaphthyleno, acephenanthtyleno, anthraceno, azuleno, benzeno (benzo),chryseno, coroneno, fluorantheno, fluoreno, hexaceno, hexapheno,hexyleno, as-indaceno, s-indaceno, indeno, naphthalene (naphtho),octaceno, octapheno, octaleno, ovaleno, penta-2,4-dieno, pentaceno,pentaleno, pentapheno, peryleno, phenaleno, phenanthreno, piceno,pleiadeno, pyreno, pyranthreno, rubiceno, triphenyleno, trinaphthaleno,and the like. Where a specific connectivity is intended, the involvedbridging carbon atoms (of the aryleno bridge) are denoted in brackets,e.g., [1,2]benzeno ([1,2]benzo), [1,2]naphthaleno, [2,3]naphthaleno,etc. Thus, in the above example, when R¹ taken together with R² is[2,3]naphthaleno, the resultant compound is anthracene. When R¹ takentogether with R² is [1,2]naphthaleno, the resultant compound isphenanthrene. In a preferred embodiment, the aryleno group is (C5-C14),with (C5-C10) being even more preferred.

The term “arylaryl” as used herein refers to a monovalent hydrocarbonradical derived by the removal of one hydrogen atom from a single carbonatom of a ring system in which two or more identical or non-identicalparent aromatic ring systems are joined directly together by a singlebond, where the number of such direct ring junctions is one less thanthe number of parent aromatic ring systems involved. Typical arylarylgroups include, but are not limited to, biphenyl, triphenyl,phenyl-naphthyl, binaphthyl, biphenyl-naphthyl, and the like. When thenumber of carbon atoms comprising an arylaryl group is specified, thenumbers refer to the carbon atoms comprising each parent aromatic ring.For example, (C1-C14) arylaryl is an arylaryl group in which eacharomatic ring comprises from 5 to 14 carbons, e.g., biphenyl, triphenyl,binaphthyl, phenylnaphthyl, etc. In some instances, each parent aromaticring system of an arylaryl group is independently a (C5-C14) aromatic ora (C1-C10) aromatic. Some preferred are arylaryl groups in which all ofthe parent aromatic ring systems are identical, e.g., biphenyl,triphenyl, binaphthyl, trinaphthyl, etc.

The term “biaryl” as used herein refers to an arylaryl radical havingtwo identical parent aromatic systems joined directly together by asingle bond. Typical biaryl groups include, but are not limited to,biphenyl, binaphthyl, bianthracyl, and the like. In some instances, thearomatic ring systems are (C5-C14) aromatic rings or (C5-C10) aromaticrings. One preferred biaryl group is biphenyl.

The term “arylalkyl” as used herein refers to an acyclic alkyl radicalin which one of the hydrogen atoms bonded to a carbon atom, typically aterminal or spa carbon atom, is replaced with an aryl radical. Typicalarylalkyl groups include, but are not limited to, benzyl,2-phenylethan-1-yl, 2-phenylethen-1-yl, naphthylmethyl,2-naphthylethan-1-yl, 2-naphthylethen-1-yl, naphthobenzyl,2-naphthophenylethan-1-yl and the like. Where specific alkyl moietiesare intended, the nomenclature arylalkanyl, arylakenyl and/orarylalkynyl is used. In some embodiments, the arylalkyl group is(C6-C40) arylalkyl, e.g., the alkanyl, alkenyl or alkynyl moiety of thearylalkyl group is (C1-C26) and the aryl moiety is (C5-C14). In somepreferred embodiments the arylalkyl group is (C6-C13), e.g., thealkanyl, alkenyl or alkynyl moiety of the arylalkyl group is (C1-C3) andthe aryl moiety is (C5-C10).

The term “heteroaryl” as used herein refers to a monovalentheteroaromatic radical derived by the removal of one hydrogen atom froma single atom of a parent heteroaromatic ring system. Typical heteroarylgroups include, but are not limited to, radicals derived from acridine,arsindole, carbazole, β-carboline, chromane, chromene, cinnoline, furan,imidazole, indazole, indole, indoline, indolizine, isobenzofuran,isochromene, isoindole, isoindo line, isoquinoline, isothiazole,isoxazole, naphthyridine, oxadiazole, oxazole, perimidine,phenanthridine, phenanthroline, phenazine, phthalazine, pteridine,purine, pyran, pyrazine, pyrazole, pyridazine, pyridine, pyrimidine,pyrrole, pyrrolizine, quinazoline, quinoline, quinolizine, quinoxaline,tetrazole, thiadiazole, thiazole, thiophene, triazole, xanthene, and thelike. In some embodiments, the heteroaryl group is a 5-14 memberedheteroaryl, with 5-10 membered heteroaryl being particularly preferred.Some preferred heteroaryl radicals are those derived from parentheteroaromatic ring systems in which any ring heteroatoms are nitrogens,such as imidazole, indole, indazole, isoindole, naphthyridine,pteridine, isoquinoline, phthalazine, purine, pyrazole, pyrazine,pyridazine, pyridine, pyrrole, quinazoline, quinoline, etc.

The term “heteroaryldiyl” refers to a divalent heteroaromatic radicalderived by the removal of one hydrogen atom from each of two differentatoms of a parent heteroaromatic ring system or by the removal of twohydrogen atoms from a single atom of a parent heteroaromatic ringsystem. The two monovalent radical centers or each valency of the singledivalent center can form bonds with the same or different atom(s).Typical heteroaryldiyl groups include, but are not limited to, divalentradicals derived from acridine, arsindole, carbazole, β-carboline,chromane, chromene, cinnoline, furan, imidazole, indazole, indole,indoline, indolizine, isobenzofuran, isochromene, isoindole,isoindoline, isoquinoline, isothiazole, isoxazole, naphthyridine,oxadiazole, oxazole, perimidine, phenanthridine, phenanthroline,phenazine, phthalazine, pteridine, purine, pyran, pyrazine, pyrazole,pyridazine, pyridine, pyrimidine, pyrrole, pyrrolizine, quinazoline,quinoline, quinolizine, quinoxaline, tetrazole, thiadiazole, thiazole,thiophene, triazole, xanthene, and the like. In some embodiments, theheteroaryldiyl group is 5-14 membered heteroaryldiyl or a 5-10 memberedheteroaryldiyl. Some preferred heteroaryldiyl groups are divalentradicals derived from parent heteroaromatic ring systems in which anyring heteroatoms are nitrogens, such as imidazole, indole, indazole,isoindole, naphthyridine, pteridine, isoquinoline, phthalazine, purine,pyrazole, pyrazine, pyridazine, pyridine, pyrrole, quinazoline,quinoline, etc.

The term “heteroaryleno” as used herein refers to a divalent bridgeradical having two adjacent monovalent radical centers derived by theremoval of one hydrogen atom from each of two adjacent atoms of a parentheteroaromatic ring system. Attaching a heteroaryleno bridge radical,e.g. pyridino, to a parent aromatic ring system, e.g. benzene, resultsin a fused heteroaromatic ring system, e.g., quinoline. The bridge isassumed to have the maximum number of non-cumulative double bondsconsistent with its attachment to the resultant fused ring system. Inorder to avoid double-counting ring atoms, when a heteroarylenosubstituent is formed by taking together two adjacent substituents on astructure that includes alternative substituents, the ring atoms of theheteroaryleno bridge replace the bridging ring atoms of the structure.As an example, consider the following structure:

wherein R¹, when taken alone is hydrogen, or when taken together with R²is 5-14 membered heteroaryleno; and R², when taken alone is hydrogen, orwhen taken together with R¹ is 5-14 membered heteroaryleno;

When R¹ and R² are each hydrogen, the resultant compound is benzene.When R1 taken together with R² is a 6-membered heteroaryleno pyridino),the resultant compound is isoquinoline, quinoline or quinolizine. WhenR¹ taken together with R² is a 10-membered heteroaryleno (e.g.,isoquinoline), the resultant compound is, e.g., acridine orphenanthridine. Typical heteroaryleno groups include, but are notlimited to, acridino, carbazolo, β-carbolino, chromeno, cinnolino,furan, imidazolo, indazoleno, indoleno, indolizino, isobenzofurano,isochromeno, isoindoleno, isoquinolino, isothiazoleno, isoxazoleno,naphthyridino, oxadiazoleno, oxazoleno, perimidino, phenanthridino,phenanthrolino, phenazino, phthalazino, pteridino, purino, pyrano,pyrazino, pyrazoleno, pyridazino, pyridino, pyrimidino, pyrroleno,pyrrolizino, quinazolino, quinolino, quinolizino, quinoxalino,tetrazoleno, thiadiazoleno, thiazoleno, thiopheno, triazoleno, xantheno,or the like. Where a specific connectivity is intended, the involvedbridging atoms (of the heteroaryleno bridge) are denoted in brackets,e.g., [1,2]pyridino, [2,3]pyridino, [3,4]pyridino, etc. Thus, in theabove example, when R¹ taken together with R² is [1,2]pyridino, theresultant compound is quinolizine. When R¹ taken together with R2 is[2,3]pyridino, the resultant compound is quinoline. When R¹ takentogether with R² is [3,4]pyridino, the resultant compound isisoquinoline. In preferred embodiments, the heteroaryleno group is 5-14membered heteroaryleno or 5-10 membered heteroaryleno. Some preferredheteroaryleno radicals are those derived from parent heteroaromatic ringsystems in which any ring heteroatoms are nitrogens, such as imidazolo,indolo, indazolo, isoindolo, naphthyridino, pteridino, isoquinolino,phthalazino, purino, pyrazolo, pyrazino, pyridazino, pyndmo, pyrrolo,quinazolino, quinolino, etc.

The term “heteroaryl-heteroaryl” as used herein refers to a monovalentheteroaromatic radical derived by the removal of one hydrogen atom froma single atom of a ring system in which two or more identical ornon-identical parent heteroaromatic ring systems are joined directlytogether by a single bond, where the number of such direct ringjunctions is one less than the number of parent heteroaromatic ringsystems involved. Typical heteroaryl-heteroaryl groups include, but arenot limited to, bipyridyl, tripyridyl, pyridylpurinyl, bipurinyl, etc.When the number of ring atoms are specified, the numbers refer to thenumber of atoms comprising each parent heteroaromatic ring systems. Forexample, 5-14 membered heteroaryl-heteroaryl is a heteroaryl-heteroarylgroup in which each parent heteroaromatic ring system comprises from 5to 14 atoms, e.g., bipyridyl, tripyridyl, etc. In some embodiments, eachparent heteroaromatic ring system is independently a 5-14 memberedheteroaromatic, more preferably a 5-10 membered heteroaromatic. Alsopreferred are heteroaryl-heteroaryl groups in which all of the parentheteroaromatic ring systems are identical. Some preferredheteroaryl-heteroaryl radicals are those in which each heteroaryl groupis derived from parent heteroaromatic ring systems in which any ringheteroatoms are nitrogens, such as imidazole, indole, indazole,isoindole, naphthyridine, pteridine, isoquinoline, phthalazine, purine,pyrazole, pyrazine, pyridazine, pyridine, pyrrole, quinazoline,quinoline, etc.

The term “biheteroaryl” as used herein refers to a heteroaryl-heteroarylradical having two identical parent heteroaromatic ring systems joineddirectly together by a single bond. Typical biheteroaryl groups include,but are not limited to, bipyridyl, bipurinyl, biquinolinyl, and thelike. In some embodiments, the heteroaromatic ring systems are 5-14membered heteroaromatic rings or 5-10 membered heteroaromatic rings.Some preferred biheteroaryl radicals are those in which the heteroarylgroups are derived from a parent heteroaromatic ring system in which anyring heteroatoms are nitrogens, such as biimidazolyl, biindolyl,biindazolyl, biisoindolyl, binaphthyridinyl, bipteridinyl,biisoquinolinyl, biphthalazinyl, bipurinyl, bipyrazolyl, bipyrazinyl,bipyridazinyl, bipyridinyl, bipyrrolyl, biquinazolinyl, biquinolinyl,etc.

The term “heteroarylalkyl” as used herein refers to an acyclic alkylradical in which one of the hydrogen atoms bonded to a carbon atom,typically a terminal or sp2 carbon atom, is replaced with a heteroarylradical. Where specific alkyl moieties are intended, the nomenclatureheteroarylalkanyl, heteroarylakenyl and/or heterorylalkynyl is used. Insome embodiments, the heteroarylalkyl group is a 6-20 memberedheteroarylalkyl, e.g., the alkanyl, alkenyl or alkynyl moiety of theheteroarylalkyl is 1-6 membered and the heteroaryl moiety is a5-14-membered heteroaryl. In some preferred embodiments, theheteroarylalkyl is a 6-13 membered heteroarylalkyl, e.g., the alkanyl,alkenyl or alkynyl moiety is 1-3 membered and the heteroaryl moiety is a5-10 membered heteroaryl.

The term “substituted” as used herein refers to a radical in which oneor more hydrogen atoms are each independently replaced with the same ordifferent substituent(s). Typical substituents include, but are notlimited to, —X, —R, —O—, ═O, —OR, —O—OR, —SR, —S—, ═S, —NRR, ═NR,perhalo (C1-C6) alkyl, —CX3, —CF3, —CN, —OCN, —SCN, —NCO, —NCS, —NO,—NO2, ═N2, —N3, —S(O)2O—, —S(O)2H, —S(O)2R, —C(O)R, —C(O)X, —C(S)R,—C(S)X, —C(O)OR, —C(O)O—, —C(S)OR, —C(O)SR, —C(S)SR, —C(O)NRR, —C(S)NRRand —C(NR)NRR, where each X is independently a halogen (e.g., —F or —Cl)and each R is independently hydrogen, alkyl, alkanyl, alkenyl, alkanyl,aryl, arylalkyl, arylaryl, heteroaryl, heteroarylalkyl orheteroaryl-heteroaryl, as defined herein. The actual substituentsubstituting any particular group will depend upon the identity of thegroup being substituted.

The term “solvate” as used herein refers to an aggregate that comprisesone or more molecules of a compound of the disclosure with one or moremolecules of solvent. The solvent may be water, in which case thesolvate may be a hydrate. Alternatively, the solvent may be an organicsolvent. Thus, the compounds of the present disclosure may exist as ahydrate, including a monohydrate, dihydrate, hemihydrate, sesquihydrate,trihydrate, tetrahydrate or the like, as well as the correspondingsolvated forms. The compound of the disclosure may be true solvates,while in other cases, the compound of the disclosure may merely retainadventitious water or be a mixture of water plus some adventitioussolvent.

The term “oxysterol” as used herein is meant to encompass one or moreforms of oxidized cholesterol. The oxysterols described herein areeither independently or collectively active to bone growth in a patient,as described in WO 2013169399 A1, which is hereby incorporated byreference in its entirety.

The oxysterol can be in a pharmaceutically acceptable salt. Someexamples of potentially pharmaceutically acceptable salts include thosesalt-forming acids and bases that do not substantially increase thetoxicity of a compound, such as, salts of alkali metals such asmagnesium, potassium and ammonium, salts of mineral acids such ashydrochloride, hydriodic, hydrobromic, phosphoric, metaphosphoric,nitric and sulfuric acids, as well as salts of organic acids such astartaric, acetic, citric, malic, benzoic, glycollic, gluconic, gulonic,succinic, arylsulfonic, e.g., p-toluenesulfonic acids, or the like.

Pharmaceutically acceptable salts of oxysterol include salts preparedfrom pharmaceutically acceptable non-toxic bases or acids includinginorganic or organic bases, inorganic or organic acids and fatty acids.Salts derived from inorganic bases include aluminum, ammonium, calcium,copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous,potassium, sodium, zinc, and the like. Salts derived frompharmaceutically acceptable organic non-toxic bases include salts ofprimary, secondary, and tertiary amines, substituted amines includingnaturally occurring substituted amines, cyclic amines, and basic ionexchange resins, such as arginine, betaine, caffeine, choline,N,N′-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol,2-dimethylaminoethanol, ethanolamine, ethylenediamine,N-ethyl-morpholine, N-ethylpiperidine, glucamine, glucosamine,histidine, hydrabamine, isopropylamine, lysine, methylglucamine,morpholine, piperazine, piperidine, polyamine resins, procaine, purines,theobromine, triethylamine, trimethyl amine, tripropylamine,tromethamine, and the like. When the compound of the current applicationis basic, salts may be prepared from pharmaceutically acceptablenon-toxic acids, including inorganic and organic acids. Such acidsinclude acetic, benzenesulfonic, benzoic, camphorsulfonic, citric,ethanesulfonic, formic, fumaric, gluconic, glutamic, hydrobromic,hydrochloric, isethionic, lactic, maleic, malic, mandelic,methanesulfonic, malonic, mucic, nitric, pamoic, pantothenic,phosphoric, propionic, succinic, sulfuric, tartaric, p-toluenesulfonicacid, trifluoroacetic acid, and the like. Fatty acid salts may also beused, e.g., fatty acid salts having greater than 2 carbons, greater than8 carbons or greater than 16 carbons, such as butyric, caproic,caprylic, capric, lauric, mystiric, palmitic, stearic, arachidic or thelike.

In some embodiments, in order to reduce the solubility of the oxysterolto assist in obtaining a controlled release depot effect, the oxysterolis utilized as the free base or utilized in a salt which has relativelylower solubility. For example, the present application can utilize aninsoluble salt such as a fatty acid salt. Representative fatty acidsalts include salts of oleic acid, linoleic acid, or fatty acid saltswith between 8 to 20 carbons solubility, such as for example, palmeateor stearate.

The terms “bioactive” composition or “pharmaceutical” composition asused herein may be used interchangeably. Both terms refer tocompositions that can be administered to a subject. Bioactive orpharmaceutical compositions are sometimes referred to herein as“pharmaceutical compositions” or “bioactive compositions” of the currentdisclosure. Sometimes the phrase “administration of Oxy133” is usedherein in the context of administration of this compound to a subject(e.g., contacting the subject with the compound, injecting the compound,administering the compound in an implant, etc.). It is to be understoodthat the compound for such a use can generally be in the form of apharmaceutical composition or bioactive composition comprising theoxysterol (e.g., Oxy133).

A “therapeutically effective amount” or “effective amount” is such thatwhen administered, the oxysterol (e.g., Oxy133) results in alteration ofthe biological activity, such as, for example, enhancing bone growth,etc. The dosage administered to a patient can be as single or multipledoses depending upon a variety of factors, including the drug'sadministered pharmacokinetic properties, the route of administration,patient conditions and characteristics (sex, age, body weight, health,size, etc.), and extent of symptoms, concurrent treatments, frequency oftreatment and the effect desired. In some embodiments the formulation isdesigned for immediate release. In other embodiments the formulation isdesigned for sustained release. In other embodiments, the formulationcomprises one or more immediate release surfaces and one or moresustained release surfaces.

A “depot” includes but is not limited to capsules, microspheres,microparticles, microcapsules, microfibers particles, nanospheres,nanoparticles, coating, matrices, wafers, pills, pellets, emulsions,liposomes, micelles, gels, or other pharmaceutical delivery compositionsor a combination thereof. Suitable materials for the depot are ideallypharmaceutically acceptable biodegradable and/or any bioabsorbablematerials that are preferably FDA approved or GRAS materials. Thesematerials can be polymeric or non-polymeric, as well as synthetic ornaturally occurring, or a combination thereof. In some embodiments, thematrix can be a biodegradable depot.

The term “implantable” as utilized herein refers to a biocompatibledevice (e.g., implant) retaining potential for successful placementwithin a mammal. The expression “implantable device” and expressions ofthe like import as utilized herein refers to an object implantablethrough surgery, injection, or other suitable means whose primaryfunction is achieved either through its physical presence or mechanicalproperties.

“Localized” delivery includes delivery where one or more drugs aredeposited within a tissue, for example, a bone cavity, or in closeproximity (within about 0.1 cm, or preferably within about 10 cm, forexample) thereto. For example, the oxysterol dose delivered locally fromthe implant may be, for example, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,90%, 95%, 99%, 99.9% or 99.999% less than the oral dosage or injectabledose.

The term “mammal” refers to organisms from the taxonomy class“mammalian,” including but not limited to humans, other primates such asmonkeys, chimpanzees, apes, orangutans and monkeys, rats, mice, rabbits,cats, dogs, pigs, cows, horses, etc.

The term “particle” refers to pieces of a substance of all shapes,sizes, thickness and configuration such as fibers, threads, narrowstrips, thin sheets, clips, shards, etc., that possess regular,irregular or random geometries. It should be understood that somevariation in dimension will occur in the production of the particles andparticles demonstrating such variability in dimensions are within thescope of the present application. For example, the mineral particles(e.g., porous ceramic) can be from about 0.5 mm to about 1.5 mm. In someembodiments, the mineral particles can be from about 0.2 mm to about 0.5mm.

In some embodiments, the medical device comprises a matrix. The “matrix”of the present application is utilized as a scaffold for bone and/orcartilage repair, regeneration, and/or augmentation. Typically, thematrix provides a 3-D matrix of interconnecting pores, which acts as ascaffold for cell migration. The morphology of the matrix guides cellmigration and cells are able to migrate into or over the matrix,respectively. The cells then are able to proliferate and synthesize newtissue and form bone and/or cartilage. In some embodiments, the matrixis resorbable.

In some embodiments, the matrix can be malleable, cohesive, flowableand/or can be shaped into any shape. The term “malleable” includes thatthe matrix is capable of being converted from a first shape to a secondshape by the application of pressure.

The term “cohesive” as used herein means that the putty tends to remaina singular, connected mass upon movement, including the exhibition ofthe ability to elongate substantially without breaking upon stretching.

The term “moldable” includes that the matrix can be shaped by hand ormachine or injected in the target tissue site (e.g., bone defect,fracture, or void) in to a wide variety of configurations. In someembodiments, the matrix can be formed into sheets, blocks, rings,struts, plates, disks, cones, pins, screws, tubes, teeth, bones, portionof bone, wedges, cylinders, threaded cylinders, or the like, as well asmore complex geometric configurations.

The term “compression” refers to a reduction in size or an increase indensity when a force is applied to the matrix.

The oxysterol can be “osteogenic,” where it can enhance or acceleratethe ingrowth of new bone tissue.

Compression resistant implants and methods of making and using thoseimplants are provided. The compression resistant implants can be formedto fit easily within a bone defect. The compression resistant implantshave mineral particles incorporated within them and also maintain thedesired combination of compressive strength and cohesiveness.Additionally, provided are compression resistant implants whichincorporate an osteogenic agent, such as an oxysterol in it.

The section headings below should not be restricted and can beinterchanged with other section headings.

Oxysterols

In some embodiments, the malleable implant can be a robust implant thatcan have a high mineral content or allograft content, still bind and becohesive. In some embodiments, there is a compression resistant implantconfigured to fit at or near a bone defect to promote bone growth, thecompression resistant implant comprising porous ceramic particles in anamount of about 30 wt % to about 99.5 wt % based on a total weight ofthe implant in a biodegradable polymer in an amount of about 0.1 wt % toabout 20 wt % based on the total weight of the implant, and an oxysteroldisposed in or on the compression resistant implant.

Oxysterols are a family of molecules consisting of oxygenatedderivatives of cholesterol. Oxysterols are involved in many biologicalprocesses, and have been found to possess osteogenic properties. Forexample, one naturally occurring oxysterol, 20(S)-hydroxycholesterol,has osteogenic and anti-adipogenic properties. Such oxysterols can beuseful in healing bone fractures, long bone fusion procedures, spinalfusion procedures, interbody spinal fusion procedures, posterolateralspinal fusion procedures, cervical discectomy and fusion procedures,dental procedures, and cranial/maxillofacial procedures.

Oxysterols also play a role in various physiological processes, such ascellular differentiation, inflammation, apoptosis, and steroidproduction. Oxysterols are products of cholesterol oxidation and areformed in vivo by a variety of cell types including osteoblasts(Schroepfer. Phyiol Rev 80:361-554, 2000; Bjorkhem and Dicsfalusy.Arterioscler Thromb Vase Biol 22:734-742, 2002). Certain oxysterols,such as 20(S)-hydroxycholesterol, as well as 22(S)- or22(R)-hydroxycholesterol, induce osteogenic differentiation inmultipotent mesenchymal cells such as M2-10B4 (M2) marrow stromal cellsand C3H10T1/2 embryonic fibroblasts (Kha et al. J Bone Miner Res19:830-840, 2004). Oxysterols can induce osteogenic and inhibitadipogenic differentiation of mesenchymal stem cells through activationof the hedgehog signaling pathway, which in turn regulates the masterswitches that control osteogenic and adipogenic differentiation, namelyRunx2 and PPARγ, respectively (Richardson et al. J Cell Biochem100:1131-1145, 2007; Dwyer et al. J Biol Chem 282: 8959-8968, 2007; Kimet al., J Bone Miner Res 22:1711-1719, 2007). Some oxysterols alsoprovide therapeutic uses for treatment of bone defects or disorders suchas osteoporosis.

The implants described herein can be useful in creating new therapeuticimplants and matrices that include an oxysterol for induction of localbone formation and treatment of bone defects. The oxysterol is retainedin the matrix and released over time, while the matrix allows influx ofbone cells to grow bone and fill the defect. In some embodiments, suchapplications are based on the ability of these oxysterol compounds toinduce the hedgehog signaling pathway. In some embodiments, the implantcauses mesenchymal stem cells to show induced expression of markers ofosteoblast differentiation. The implants and matrices described hereincan be used for a variety of therapeutic uses including but not limitedto induction of local bone formation and treatment of bone defects. Insome embodiments, implants containing oxysterol as described hereininduce a biological response when the implant contacts a human or animalcell. In some embodiments, the cell can be a mesenchymal stem cell or abone marrow stromal cell. In some embodiments, the biological responsecomprises stimulating osteoblastic differentiation, inhibiting adipocytedifferentiation, or stimulating cartilage formation. In someembodiments, the implant is configured as an implant to release theoxysterol to induce a biological response at or near a surgical site ora bone defect site.

Oxysterols can be used to induce systemic bone formation to treat bonedefects such as osteoporosis, to induce local bone formation to treatconditions such as nonunion fractures, or other bone disorders, such asjaw bone defects in dental applications/implants, and to induce spinalfusion. In some embodiments, the implant may include an oxysterol aloneor in combination with one or more bone morphogenetic proteins orosteogenic agents. In some embodiments, more than one oxysterol ispresent in the implant. In some embodiments, the implants include Oxy133and/or Oxy153.

In some embodiments, the implant or matrix includes oxysterols which aidin osteogenesis. In some embodiments, the implant or matrix includesOxy34, Oxy49, and/or Oxy133. In some embodiments, the implant or matrixincludes an oxysterol comprising the structure:

or a pharmaceutically acceptable salt, hydrate or solvate thereof,wherein R1 comprises an aliphatic or cyclic substituent having at leastone carbon atom.

In some embodiments, R comprises an alkyl, a heteroalkyl, an alkanyl, aheteroalkanyl, an alkenyl, a heteroalkenyl, an alkynyl, a heteroalkanyl,an alkyldiyl, a heteroalkyldiyl, an alkyleno, a heteroalkyleno, an aryl,an aryldiyl, an arydeno, an arylaryl, a biaryl, an arylalkyl, aheteroaryl, a heteroaryldiyl, a heteroaryleno, a heteroaryl-heteroaryl,a biheteroaryl, a heteroarylalkyl or combinations thereof. In someembodiments, the R substituent comprises a (C1-C20) alkyl orheteroalkyl, a (C₂-C₂₀) aryl or heteroaryl, a (C₆-C₂₆) arylalkyl orheteroalkyl and a (C₅-C₂₀) arylalkyl or heteroaryl-heteroalkyl, a(C₄-C₁₀) alkyldiyl or heteroalkyldiyl, or a (C₄-C₁₀) alkyleno orheteroalkyleno. The R substituent may be cyclic or acyclic, branched orunbranched, substituted or unsubstituted, aromatic, saturated orunsaturated chains, or combinations thereof. In some embodiments, the Rsubstituent is an aliphatic group. In some embodiments, the Rsubstituent is a cyclic group. In some embodiments, the R substituent isa hexyl group.

The present disclosure includes an implant or matrix including anosteogenic oxysterol (e.g., Oxy133) and its ability to promoteosteogenic differentiation in vitro. Oxy133 is a particularly effectiveosteogenic agent. In various applications, Oxy133 is useful in treatingconditions that would benefit from localized stimulation of boneformation, such as, for example, spinal fusion, fracture repair, boneregenerative/tissue applications, augmentation of bone density in thejaw for dental implants, osteoporosis or the like. One particularadvantage of Oxy133 is that it provides greater ease of synthesis andimproved time to fusion when compared to other osteogenic oxysterols.Oxy133 is a small molecule that can serve as an anabolic therapeuticagent for bone growth, as well as a useful agent for treatment of avariety of other conditions.

One aspect of the application disclosure is an implant or a matrixincluding Oxy133, having the formula:

or a pharmaceutically acceptable salt, solvate or hydrate thereof. TheOxy133 may be used as a bioactive or pharmaceutical compositioncomprising Oxy133 or a pharmaceutically acceptable salt, solvate orhydrate thereof and a pharmaceutically acceptable carrier. Oxy133 hasthe IUPAC designation (3S,5S,6S,8R,9S,10R,13S,14S,17S)-17-((S)-2-hydroxyoctan-2-yl)-10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthrene-3,6-diol.

Another aspect of the disclosure is a method for inducing (stimulating,enhancing) a hedgehog (Hh) pathway mediated response, in a cell ortissue, comprising contacting the cell or tissue with a therapeuticallyeffective amount of Oxy133. The cell or tissue can be in vitro or in asubject, such as a mammal. The hedgehog (Hh) pathway mediated responseinvolves the stimulation of osteoblastic differentiation,osteomorphogenesis, and/or osteoproliferation; the stimulation of hairgrowth and/or cartilage formation; the stimulation of neovasculogenesis,e.g., angiogenesis, thereby enhancing blood supply to ischemic tissues;or it is the inhibition of adipocyte differentiation, adipocytemorphogenesis, and/or adipocyte proliferation; or the stimulation ofprogenitor cells to undergo neurogenesis. The Hh mediated response cancomprise the regeneration of any of a variety of types of tissues, foruse in regenerative medicine. Another aspect of the disclosure is amethod for treating a subject having a bone disorder, osteopenia,osteoporosis, or a bone fracture, comprising administering to thesubject an effective amount of a bioactive composition or pharmaceuticalcomposition comprising Oxy133. The subject can be administered thebioactive composition or pharmaceutical composition at a therapeuticallyeffective dose in an effective dosage form at a selected interval to,e.g., increase bone mass, ameliorate symptoms of osteoporosis, reduce,eliminate, prevent or treat atherosclerotic lesions, or the like. Thesubject can be administered the bioactive composition or pharmaceuticalcomposition at a therapeutically effective dose in an effective dosageform at a selected interval to ameliorate the symptoms of osteoporosis.In some embodiments, a composition comprising Oxy133 may includemesenchymal stem cells to induce osteoblastic differentiation of thecells at a targeted surgical area.

In various aspects, the Oxy133 can be administered to a cell, tissue ororgan by local administration. For example, the Oxy133 can be appliedlocally with a cream or the like, or it can be injected or otherwiseintroduced directly into a cell, tissue or organ, or it can beintroduced with a suitable medical device, such as an implant asdiscussed herein.

In some embodiments, the dosage of Oxy133 is from approximately 10pg/day to approximately 80 g/day. In some embodiments, the dosage ofOxy133 is from approximately 1.0 g/day, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0,4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0,11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0,17.5, 18.0, 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, 22.0, 22.5, 23.0,23.5, 24.0, 24.5, 25.0, 25.5, 26.0, 26.5, 27.0, 27.5, 28.0, 28.5, 29.0,29.5, 30.0, 30.5, 31.0, 31.5, 32.0, 32.5, 33.0, 33.5, 34.0, 34.5, 35.0,35.5, 36.0, 36.5, 37.0, 37.5, 38.0, 38.5, 39.0, 39.5, 40.0, 40.5, 41.0,41.5, 42.0, 42.5, 43.0, 43.5, 44.0, 44.5, 45.0, 45.5, 46.0, 46.5, 47.0,47.5, 48.0, 48.5, 49.0, 49.5 50.0, 50.5, 51.0, 51.5, 52.0, 52.5, 53.0,53.5, 54.0, 54.5, 55.0, 55.5, 56.0, 56.5, 57.0, 57.5, 58.0, 58.5, 59.0,59.5 to about 60.0 grams/day. Additional dosages of Oxy133 include fromapproximately 2.4 ng/day to approximately 50 mg/day; approximately 50ng/day to approximately 2.5 mg/day; approximately 250 ng/day toapproximately 250 mcg/day; approximately 250 ng/day to approximately 50mcg/day; approximately 250 ng/day to approximately 25 mcg/day;approximately 250 ng/day to approximately 1 mcg/day; approximately 300ng/day to approximately 750 ng/day or approximately 0.50 mcg/day to 500ng/day. In various embodiments, the dose may be about 0.01 toapproximately 10 mcg/day or approximately 1 ng/day to about 120 mcg/day.In some embodiments, the dosage of Oxy133 is in greater amounts. Forexample, in some embodiments, the dosage of Oxy133 is from 0.01 mg/dayto 5 g/day.

The matrix can comprise the oxysterol (e.g., Oxy133) disposedhomogenously throughout it or in discrete regions or discrete layers ofthe matrix. The oxysterol can be loaded in the matrix and can comprisefrom about 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6,0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5,4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5,11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5,17.0, 17.5, 18.0, 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, 22.0, 22.5,23.0, 23.5, 24.0, 24.5, 25.0, 25.5, 26.0, 26.5, 27.0, 27.5, 28.0, 28.5,29.0, 29.5, 30.0, 30.5, 31.0, 31.5, 32.0, 32.5, 33.0, 33.5, 34.0, 34.5,35.0, 35.5, 36.0, 36.5, 37.0, 37.5, 38.0, 38.5, 39.0, 39.5, 40.0, 40.5,41.0, 41.5, 42.0, 42.5, 43.0, 43.5, 44.0, 44.5, 45.0, 45.5, 46.0, 46.5,47.0, 47.5, 48.0, 48.5, 49.0, 49.5, 50.0, 50.5, 51.0, 51.5, 52.0, 52.5,53.0, 53.5, 54.0, 54.5, 55.0, 55.5, 56.0, 56.5, 57.0, 57.5, 58.0, 58.5,59.0, 59.5 to about 60% w/v, w/w and/or v/v of the total weight of thematrix.

The oxysterol can be loaded in the matrix and can comprise from about0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7,0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0,5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5,12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5,18.0, 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, 22.0, 22.5, 23.0, 23.5,24.0, 24.5, 25.0, 25.5, 26.0, 26.5, 27.0, 27.5, 28.0, 28.5, 29.0, 29.5,30.0, 30.5, 31.0, 31.5, 32.0, 32.5, 33.0, 33.5, 34.0, 34.5, 35.0, 35.5,36.0, 36.5, 37.0, 37.5, 38.0, 38.5, 39.0, 39.5, 40.0, 40.5, 41.0, 41.5,42.0, 42.5, 43.0, 43.5, 44.0, 44.5, 45.0, 45.5, 46.0, 46.5, 47.0, 47.5,48.0, 48.5, 49.0, 49.5, 50.0, 50.5, 51.0, 51.5, 52.0, 52.5, 53.0, 53.5,54.0, 54.5, 55.0, 55.5, 56.0, 56.5, 57.0, 57.5, 58.0, 58.5, 59.0, 59.5to about 60 mg/cc of the matrix. In some embodiments, the oxysterol canbe loaded into the matrix in an amount of about 400 mg/cc. In someembodiments, the oxysterol can be loaded into the matrix in an amount ofabout 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190,200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330,340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470,480, 490, to about 500 mg/cc. In some embodiments, 400 mg/cc can beloaded in the matrix.

In addition to the compound Oxy133, other embodiments of the disclosureencompass any and all individual stereoisomers at any of thestereocenters present in Oxy133, including diastereomers, racemates,enantiomers, and other isomers of the compound. In embodiments of thedisclosure, Oxy133 may include all polymorphs, solvates or hydrates ofthe compound, such as hydrates and those formed with organic solvents.

The ability to prepare salts depends on the acidity or basicity of acompound. Suitable salts of the compound include, but are not limitedto, acid addition salts, such as those made with hydrochloric,hydrobromic, hydroiodic, perchloric, sulfuric, nitric, phosphoric,acetic, propionic, glycolic, lactic, pyruvic, malonic, succinic, maleic,fumaric, malic, tartaric, citric, benzoic, carbonic cinnamic, mandelic,methanesulfonic, ethanesulfonic, hydroxyethanesulfonic,benezenesulfonic, p-toluene sulfonic, cyclohexanesulfamic, salicyclic,p-aminosalicylic, 2-phenoxybenzoic, and 2-acetoxybenzoic acid; saltsmade with saccharin; alkali metal salts, such as sodium and potassiumsalts; alkaline earth metal salts, such as calcium and magnesium salts;and salts formed with organic or inorganic ligands, such as quaternaryammonium salts. Additional suitable salts include, but are not limitedto, acetate, benzenesulfonate, benzoate, bicarbonate, bisulfate,bitartrate, borate, bromide, calcium edetate, camsylate, carbonate,chloride, clavulanate, citrate, dihydrochloride, edetate, edisylate,estolate, esylate, fumarate, gluceptate, gluconate, glutamate,glycollylarsanilate, hexylresorcinate, hydrabamine, hydrobromide,hydrochloride, hydroxynaphthoate, iodide, isothionate, lactate,lactobionate, laurate, malate, maleate, mandelate, mesylate,methylbromide, methylnitrate, methylsulfate, mucate, napsylate, nitrate,N-methylglucamine ammonium salt, oleate, pamoate (embonate), palmitate,pantothenate, phosphate/diphosphate, polygalacturonate, salicylate,stearate, sulfate, subacetate, succinate, tannate, tartrate, teoclate,tosylate, triethiodide and valerate salts of the compounds.

In various embodiments, Oxy133 includes one or more biologicalfunctions. That is, Oxy133 can induce a biological response whencontacted with a mesenchymal stem cell or a bone marrow stromal cell.For example, Oxy133 may stimulate osteoblastic differentiation. In someembodiments, a bioactive composition including Oxy133 may include one ormore biological functions when administered to a mammalian cell, forexample, a cell in vitro or a cell in a human or an animal. For example,such a bioactive composition may stimulate osteoblastic differentiation.In some embodiments, such a biological function can arise fromstimulation of the hedgehog pathway.

Purification of Oxy133

In some embodiments, the oxysterol, for example Oxy133, is highlypurified. In some embodiments, the Oxy133 may be crystallized orrecrystallized. In some embodiments, purified Oxy133 is formed byrecrystallizing Oxy133 in a 3:1 mixture of acetone/water, as shownbelow:

As shown above, upon crystallization, the purified Oxy133 forms ahydrate. However, in some embodiments, the Oxy133 is in the anhydrousform. In some embodiments, the percent crystallinity of any of thecrystalline forms of Oxy133 described herein can vary with respect tothe total amount of Oxy133.

In certain embodiments the Oxy 133 can have a percent crystallinity of asalt, hydrate, solvate or crystalline form of Oxy133 to be at least 10%,at least 20%, at least 30%, at least 40%, at least 50%, at least, 60%,at least 70%, at least 80%, at least 90%, at least 95%, or at least 99%.In some embodiments, the percent crystallinity can be substantially100%, where substantially 100% indicates that the entire amount ofOxy133 appears to be crystalline as best can be determined using methodsknown in the art. Accordingly, therapeutically effective amounts ofOxy133 can include amounts that vary in crystallinity. These includeinstances where an amount of the crystallized Oxy133 in a solid form issubsequently dissolved, partially dissolved, or suspended or dispersedin a liquid.

In one embodiment, the purified Oxy133 is crystallized as a monohydrate.However, in other embodiments the purified Oxy133 may be crystallized inother hydrous forms, such as, for example, a dihydrate, a hemihydrate, asesquihydrate, a trihydrate, a tetrahydrate and the like, as well as thecorresponding solvated forms. In some embodiments, the Oxy133 iscrystallized in an amorphous form. In other embodiments, the purifiedOxy133 is crystallized as a co-crystal or a pharmaceutically acceptablesalt.

In some embodiments, the oxysterol (e.g., Oxy 133) that can be used canbe in amorphous form and have faster dissolution and release from thematrix. Such as, for example, a burst release from the matrix of fromabout 10%, 15%, 20%, 25%, 30%, 35%, 45%, to about 50% of the oxysterolover 24 or 48 hours.

In some embodiments, the unpurified Oxy133 may be solidified by mixingwith heptanes. The product may be subsequently filtered and suspended inmethylene chloride. In some embodiments, the unpurified Oxy133 may befiltered from the suspension and crystallized with the use of acetoneand water or other organic or inorganic solvents (e.g., diethyl ether,dichloromethane, ethyl acetate, acetone, n,n-dimethylformamide,acetonitrile, dimethyl sulfoxide, ammonia, t-butanol, n-propanol,ethanol, methanol, acetic acid or a combination thereof).

In various embodiments, the unpurified Oxy133 may be isolated andpurified by any other traditional means. That is, the unpurified Oxy133can be isolated and purified to the desired purity, e.g., from about 95%to about 99.9% by filtration, centrifugation, distillation to separatevolatile liquids on the basis of their relative volatilities,crystallization, recrystallization, evaporation to remove volatileliquids from non-volatile solutes, solvent extraction to removeimpurities, dissolving the composition in a solvent in which othercomponents are soluble therein or other purification methods.

In some embodiments, the purified Oxy133 is formed in crystal form viacrystallization, which separates the Oxy133 from the liquid feed streamby cooling the liquid feed stream or adding precipitants which lower thesolubility of byproducts and unused reactants in the reaction mixture sothat the Oxy133 forms crystals. In some embodiments, the solid crystalsare then separated from the remaining liquor by filtration orcentrifugation. The crystals can be resolubilized in a solvent and thenrecrystallized and the crystals are then separated from the remainingliquor by filtration or centrifugation to obtain a highly pure sample ofOxy133. In some embodiments, the crystals can then be granulated to thedesired particle size. For example, the mineral particles (e.g., porousceramic) can be from about 0.5 mm to about 1.5 mm. In some embodiments,the mineral particles can be from about 0.2 mm to about 0.5 mm.

In some embodiments, the unpurified Oxy133 can be purified where thepurified Oxy133 is formed in crystalized form in a solvent and thenremoved from the solvent to form a high purity Oxy133 having a purity offrom about 98% to about 99.99%. In some embodiments, the Oxy133 can berecovered via filtration or vacuum filtration before or afterpurification.

Implants and Uses

In some embodiments, the implant comprises a matrix that provides atissue scaffold for cells to guide the process of tissue formation invivo in three dimensions. In some embodiments, the implant provides aporous scaffold to promote bone ingrowth. The morphology of the matrixguides cell migration and cells are able to migrate into or over thematrix. The cells then are able to proliferate and synthesize new tissueand form bone and/or cartilage. In some embodiments, one or more tissuematrices are stacked on one another.

Compression resistant matrices are provided that improve stability andmechanical strength and resists shifting, extrusion and rotation afterimplantation. In some embodiments, a compression resistant implantconfigured to fit at or near a bone defect to promote bone growth isprovided. The compression resistant implant comprises porous ceramicparticles in a biodegradable polymer, and an oxysterol disposed in or onthe compression resistant implant.

In some embodiments, the matrix of the present application can reduce orprevent compression of the implantable matrix from occurring.Oftentimes, compression of the implantable matrix causes an active agentcontained within the matrix (e.g. an oxysterol) to be forced intosurrounding environment, which may lead to unwanted adverse events suchas local transient bone resorption. This may result in poor integrationof the implant with surrounding host tissue and a failed repair. Thus,by employing a compression resistant implant, unwanted leakage of theoxysterol is reduced or avoided. In some embodiments, localized releaseof the oxysterol may cause local irritation to the surrounding tissue.In some embodiments, the leaking of oxysterol from the implant mayreduce a stable microenvironment for new bone and/or cartilage growth.It also may cause the implant to fail to retain its full efficacy overtime to maximally promote bone growth at a target site.

In some embodiments, the oxysterol (e.g., Oxy133) is evenly distributedthroughout the interior of the matrix to facilitate uniform bone growththroughout the whole matrix. In some embodiments, the oxysterol (e.g.,Oxy133) is temporarily retained within the matrix so as to limit newbone formation to within the matrix.

By reducing compression, the matrix described herein allows theoxysterol to stay evenly distributed within the interior of the matrixand thus avoids uneven distribution of the oxysterol, for example, wherea low dose of oxysterol is distributed in the upper portion of thematrix, which may promote cartilage or soft tissue formation at thetarget tissue site.

In some embodiments, the implant is in a dry cohesive mass. In someembodiments, the implant comprises a cohesive mass of a biodegradablepolymer, porous ceramic particles and an oxysterol. The biodegradablepolymer, porous ceramic particles and oxysterol comprise fibers, chipsor particles which form a coherent mass without any additional carrier.In some embodiments, the fibers, chips or particles are processed insuch a way to provide for cohesion between biodegradable polymer, porousceramic particles and an oxysterol without additional containment orbinding agents. In some embodiments, for example, the biodegradablepolymer may be milled to create curled fibers. The fibers and particlesbecome physically entangled by surface to surface interactions betweenadjacent fibers, chips and/or particles. In some embodiments, theentanglement/interaction of the fibers, chips and/or particles isresponsible for the cohesiveness of the implant prior to being wettedwith a fluid. Thus, in some embodiments, the implant comprises fibers,chips and/or particles having a size and shape that provides forincreased surface area and the ability to mechanically interlock withone another to form a coherent mass.

In some embodiments, the implant is a dry mass of a biodegradablepolymer, porous ceramic particles and an oxysterol. Each of thebiodegradable polymer, porous ceramic particles and an oxysterolcomprises particles which are homogenously mixed with each other. Asshown in FIG. 1, the powder components of matrix 10 comprise at leastthree components that have been wetted with a fluid. In someembodiments, matrix 10 comprises a biodegradable polymer 12, porousceramic particles 14 and an oxysterol 16. In some embodiments, thematrix also comprises an expandable phase, such as, for example,carboxymethylcellulose or other cellulose derivatives. As shown in FIG.1, the matrix exists as a mixture of particles which may be mechanicallybound to one another to improve holding properties. In some embodiments,the biodegradable polymer 12, porous ceramic particles 14 and oxysterol16 are homogenously dispersed so that once the matrix is wetted, theimplant will have uniform properties throughout.

The dried implant material comprises a porous body that includes aparticulate porous ceramic material having an average particle diameterof about 0.4 mm to about 5.0 mm homogenously mixed with a biodegradablepolymer. In some embodiments, the porous ceramic particles have anaverage particle size of about 0.5 mm to about 1.5 mm. In someembodiments, the porous ceramic particles have an average particle sizeof about 125 micrometers to about 750 micrometers.

In some embodiment, the particulate porous ceramics (e.g., TCP: HA) canbe homogenously disposed throughout the matrix at a particle size offrom about 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19,0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31,0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43,0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55,0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67,0.68, 0.69, 0.7, 071, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79,0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91,0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.0, 1.25, 1.4, 1.5,1.6, 1.7, 1.8, 1.9, 2.0, 2.25 to about 2.5 mm. These particles can be inthe form of granules, chips, fibers or a combination thereof.

In various embodiments, the particle size distribution of thebiodegradable polymer may be about 10 micrometers, 13 micrometers, 85micrometers, 100 micrometers, 151 micrometers, 200 micrometers and allsubranges therebetween. In some embodiments, at least 75% of theparticles have a size from about 10 micrometers to about 200micrometers. In some embodiments, at least 85% of the particles have asize from about 10 micrometers to about 200 micrometers. In someembodiments, at least 95% of the particles have a size from about 10micrometers to about 200 micrometers. In some embodiments, all of theparticles have a size from about 10 micrometers to about 200micrometers. In some embodiments, at least 75% of the particles have asize from about 20 micrometers to about 180 micrometers. In someembodiments, at least 85% of the particles have a size from about 20micrometers to about 180 micrometers. In some embodiments, at least 95%of the particles have a size from about 20 micrometers to about 180micrometers. In some embodiments, all of the particles have a size fromabout 20 micrometers to about 180 micrometers.

In some embodiments, the one or more oxysterols may for example have anaverage particle size of from about 2.2 to about 10 microns. In someembodiments the oxysterol particles have a minimum average particle sizeof about 2.2 microns, or about 2.5 microns, or about 3 microns, or about4 microns. The particles also may have a maximum average particle sizeof about 10 microns, or about 8 microns, or about 7 microns, or about 5microns. In some embodiments, the oxysterol has a particle size fromabout 5 to 30 micrometers, or about 2 microns to about 20 microns, orfrom 30 microns to 100 microns, however, in various embodiments, rangesfrom about 1 micron to 250 microns may be used. In some embodiments, theoxysterol has a particle size of about 0.1 nm to about 1 micron toprovide enhanced dissolution and quicker release of from the implant. Insome embodiments, the oxysterol (e.g., Oxy 133) is in nanoparticle formand from about 10.0, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130,140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270,280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410,420, 430, 440, 450, 460, 470, 480, 490, to about 500 nm in diameter.

In some embodiments, the oxysterol includes a particle size of about 0.1mm to about 5 mm to lengthen the release duration from the implant byslowing down Oxy133 dissolution rate which might modulate boneformation. Moreover, the oxysterol particles may have a monophasicdistribution. Additionally, in some embodiments, it may be preferable tohave a water-soluble oxysterol in order to produce an acuteanti-inflammatory/analgesic effect that the implant is not providing.

In various embodiments, the oxysterol is in the form of a solvate,hydrate or a pharmaceutically acceptable salt. The oxysterol mayalternatively be crystallized in an amorphous form. In some embodiments,the oxysterol is in the form of a monohydrate. In some embodiments, theoxysterol (e.g., Oxy 133) may be in amorphous form. In variousembodiments, the implant comprises Oxy133 and a biodegradable polymer inamorphous, crystalline or semicrystalline form; where the crystallineform may include polymorphs, solvates or hydrates.

In some embodiments, a matrix of the present application includes anoxysterol in an amount from about 0.1 mg/cc to about 500 mg/cc. Thematrix may include the oxysterol in an amount of from about 10 mg/cc, 20mg/cc, 25 mg/cc, 30 mg/cc, 40 mg/cc, 50 mg/cc, 60 mg/cc, 70 mg/cc, 80mg/cc, 90 mg/cc, 100 mg/cc, 110 mg/cc, 120 mg/cc, 130 mg/cc, 140 mg/cc,150 mg/cc, 160 mg/cc, 170 mg/cc, 180 mg/cc, 190 mg/cc, 200 mg/cc, 210mg/cc, 220 mg/cc, 230 mg/cc, 240 mg/cc, 250 mg/cc, 260 mg/cc, 270 mg/cc,280 mg/cc, 290 mg/cc, 300 mg/cc, 310 mg/cc, 320 mg/cc, 330 mg/cc, 340mg/cc, 350 mg/cc, 360 mg/cc, 370 mg/cc, 380 mg/cc, 390 mg/cc, 400 mg/cc,410 mg/cc, 420 mg/cc, 430 mg/cc, 440 mg/cc, 450 mg/cc, 460 mg/cc, 470mg/cc, 480 mg/cc, 490 mg/cc, to about 500 mg/cc or any amounttherebetween. In some embodiments, the matrix releases 40 ng to about 5mg of the oxysterol every hour.

In some embodiments, the oxysterol comprises a range of about 5.0 wt %to about 45 wt % based on the total weight of the matrix or the implantprior to or after being wetted. In some embodiments, the implantcomprises at least one biodegradable material in a wt % of about 6%, 7%,8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%,23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%,37%, 38%, 39%, 40%, 41%, 42%, 43%, or 44% based on the total weight ofthe matrix or the implant.

In some embodiments, the matrix containing the oxysterol may have aburst release surface that releases about 10%, 15%, 20%, 25%, 30%, 35%,45%, to about 50% of the oxysterol over 24 or 48 hours.

In some embodiments, the matrix releases the oxysterol over a period of1-90 days, 1-10 days, 1-3 days, 3-7 days, 3-12 days; 3-14 days, 7-10days, 7-14 days, 7-21 days, 7-30 days, 7-50 days, 7-90 days, 7-140 days,14-140 days, 3 days to 135 days, 3 days to 180 days, or 3 days to 6months. In some embodiments, bone growth will be observed over a periodof at least 14 days, for example, 14-90 days, 14-30 days, 14-60 days,21-90 days, 21-180 days; 14-210 days, or 14 days to 6 months.

In some embodiments, the one or more biodegradable polymers (e.g.,collagen) comprises 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5,6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0,12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0,18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, 22.0, 22.5, 23.0, 23.5, 24.0,24.5, 25.0, 25.5, 26.0, 26.5, 27.0, 27.5, 28.0, 28.5, 29.0, 29.5, 30.0,30.5, 31.0, 31.5, 32.0, 32.5, 33.0, 33.5, 34.0, 34.5, 35.0, 35.5, 36.0,36.5, 37.0, 37.5, 38.0, 38.5, 39.0, 39.5, 40.0, 40.5, 41.0, 41.5, 42.0,42.5, 43.0, 43.5, 44.0, 44.5, 45.0, 45.5, 46.0, 46.5, 47.0, 47.5, 48.0,48.5, 49.0, 49.5, 50.0% w/w, w/v or v/v of the matrix.

In some embodiments, the implant is wetted to form a malleable matrix.The malleable matrix is configured to be moldable to any desired shapeto fit a bone defect site. In some embodiments, the malleable implantmay be molded to fit into a surgical site, such as a bone defect site.The shape of the matrix may be tailored to the site at which it is to besituated. For example, it may be in the shape of a morsel, a plug, apin, a peg, a cylinder, a block, a wedge, a sheet, a strip, etc. Theterm “shape” refers to a determined or regular form or configuration incontrast to an indeterminate or vague form or configuration (as in thecase of a lump or other solid mass of no special form) and ischaracteristic of such materials as sheets, plates, disks, cores, tubes,wedges, cylinders, or the like. This includes forms ranging fromregular, geometric shapes to irregular, angled, or non-geometric shapes,or combinations of features having any of these characteristics. In someembodiments, the implant is malleable prior to being implanted into asurgical site. In such embodiments, a medical practitioner may mold theimplant to a desired shape and allow the implant to cure or dry prior toimplantation. In some embodiments, the implant is malleable in vivo. Insuch embodiments, a medical practitioner may mold the implant directlyinto a bone defect site. The implant is malleable and configured to bepressed into a bone defect site to fill out all crevices in a bonedefect site. In some embodiments, the implant is malleable when wettedand is configured to remain malleable while in contact with a bonedefect site.

In some embodiments, the malleable matrix can be formed to fit into thevoid space of an interbody cage or around the outside of the cage in theintervertebral space.

The dry, coherent mass may be wetted or hydrated with a variety offluids to form a malleable and moldable implant. In some embodiments,the matrix is wetted with sterile water, physiological saline, sodiumchloride, dextrose, Lactated Ringer's solution, PBS, blood, bone marrowaspirate, bone marrow fractions or a combination thereof. The amount offluid that the matrix can be wetted with includes from about 0.25, 0.5,1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5,8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5,14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5,20.0, 20.5, 21.0, 21.5, 22.0, 22.5, 23.0, 23.5, 24.0, 24.5, 25.0, 25.5,26.0, 26.5, 27.0, 27.5, 28.0, 28.5, 29.0, 29.5, 30.0, 30.5, 31.0, 31.5,32.0, 32.5, 33.0, 33.5, 34.0, 34.5, 35.0, 35.5, 36.0, 36.5, 37.0, 37.5,38.0, 38.5, 39.0, 39.5, 40.0, 40.5, 41.0, 41.5, 42.0, 42.5, 43.0, 43.5,44.0, 44.5, 45.0, 45.5, 46.0, 46.5, 47.0, 47.5, 48.0, 48.5, 49.0, 49.5to about 50.0 mls.

In some embodiments, the bone repair composition is hydrated withhyaluronic acid, cellulose ethers (such as carboxymethyl cellulose),collagen, gelatin, autoclaved bone powder, osteoconductive carriers,whole blood, blood fractions, bone marrow aspirate, concentrated bonemarrow aspirate, and mixtures thereof. Non-limiting examples of bloodfractions include serum, plasma, platelet-rich plasma, concentratedplatelet-rich plasma, platelet-poor plasma, and concentrated plateletpoor plasma. After hydrating, the bone repair composition becomes aputty or a paste that can be molded into a predetermined shape oradministered to a bone defect and manipulated to conform to the bonedefect in such a manner that will promote healing. For example, thecomposition may be hydrated with about 2 ml of saline blood per 2.5 g ofcombined DBM and periosteal powder.

FIG. 2 illustrates an implant 20 comprising a matrix as shown in FIG. 1that has been wetted with a suitable fluid. Implant 20 has been wettedwith blood to take on a red color, and molded to the shape of acylinder. FIG. 3 shows implant 20 which has been wetted with blood andmolded into a spherical shape. FIG. 4 shows implant 20 which has beenwetted with saline to take on a white color, and molded into acylindrical shape. FIG. 5 shows implant 20 which has been wetted withsaline and molded into a spherical shape. Implant 20 is wetted with asufficient amount of blood so as to prevent fissuring of the implantwhen shaped by a medical practitioner. Implant 20 has a biodegradablepolymer, porous ceramic particles and oxysterol which are homogenouslydispersed such that the implant will have uniform properties throughout.In some embodiments, implant 20 includes regions having disproportionateamounts of one or more components. For example, in some embodiments,implant 20 may have a region of relatively higher concentrated porousceramic particles to impart increased properties of compressionresistance to one or more regions of implant 20.

In some embodiments, the implant comprises a porous matrix configured toallow influx of at least bone and/or cartilage cells therein. In someembodiments, the matrix is also configured to release an active agent,such as an oxysterol. By “porous,” it is meant that the matrix has aplurality of pores. The pores of the matrix are a size large enough toallow influx of blood, other bodily fluid, and progenitor and/or boneand/or cartilage cells into the interior to guide the process of tissueformation in vivo in three dimensions.

In some embodiments, the matrix comprises a plurality of pores. In someembodiments, at least 10% of the pores are between about 50 micrometersand about 500 micrometers at their widest points. In some embodiments,at least 20% of the pores are between about 50 micrometers and about 250micrometers at their widest points. In some embodiments, at least 30% ofthe pores are between about 50 micrometers and about 150 micrometers attheir widest points. In some embodiments, at least 50% of the pores arebetween about 10 micrometers and about 500 micrometers at their widestpoints. In some embodiments, at least 90% of the pores are between about50 micrometers and about 250 micrometers at their widest points. In someembodiments, at least 95% of the pores are between about 50 micrometersand about 150 micrometers at their widest points. In some embodiments,100% of the pores are between about 10 micrometers and about 500micrometers at their widest points.

In some embodiments, the matrix has a porosity of at least about 30%, atleast about 50%, at least about 60%, at least about 70%, at least about90% or at least about 95%, or at least about 99%. The pores may supportingrowth of cells, formation or remodeling of bone, cartilage and/orvascular tissue.

In some embodiments, the porous ceramic particles form a ceramicskeleton, the skeleton having pores in the range of 1-10 mm in diameter,and a total porosity of 50-98%. In some embodiments, the porous skeletonhas pores of about 0.01 mm to about 50.0 mm in diameter. In someembodiments, the porous skeleton has pores of about 0.1 mm to about 20.0mm in diameter.

In some embodiments, an oxysterol, such as Oxy133, is administered in animplant that is solid or in semi-solid form. The solid or semi-solidform of the device may have a pre-dosed viscosity in the range of about1 to about 2000 centipoise (cps), 1 to about 200 cps, or 1 to about 100cps. In various embodiments, the semi-solid or solid implant maycomprise a biodegradable polymer having a molecular weight (MW), asshown by the inherent viscosity, from about 0.10 dL/g to about 1.2 dL/gor from about 0.20 dL/g to about 0.50 dL/g. Other IV ranges include butare not limited to about 0.05 to about 0.15 dL/g, about 0.10 to about0.20 dL/g, about 0.15 to about 0.25 dL/g, about 0.20 to about 0.30 dL/g,about 0.25 to about 0.35 dL/g, about 0.30 to about 0.35 dL/g, about 0.35to about 0.45 dL/g, about 0.40 to about 0.45 dL/g, about 0.45 to about0.55 dL/g, about 0.50 to about 0.70 dL/g, about 0.55 to about 0.6 dL/g,about 0.60 to about 0.80 dL/g, about 0.70 to about 0.90 dL/g, about 0.80to about 1.00 dL/g, about 0.90 to about 1.10 dL/g, about 1.0 to about1.2 dL/g, about 1.1 to about 1.3 dL/g, about 1.2 to about 1.4 dL/g,about 1.3 to about 1.5 dL/g, about 1.4 to about 1.6 dL/g, about 1.5 toabout 1.7 dL/g, about 1.6 to about 1.8 dL/g, about 1.7 to about 1.9dL/g, or about 1.8 to about 2.1 dL/g.

In some embodiments, the matrix has a modulus of elasticity in the rangeof about 1×10² to about 6×10⁵ dyn/cm², or 2×10⁴ to about 5×10⁵ dyn/cm²,or 5×10⁴ to about 5×10⁵ dyn/cm². In some embodiments, the matrix is inthe form of a solid or semi-solid.

In some embodiments, the matrix has a density of between about 1.6g/cm³, and about 0.05 g/cm³. In some embodiments, the matrix has adensity of between about 1.1 g/cm³, and about 0.07 g/cm³. For example,the density may be less than about 1 g/cm³, less than about 0.7 g/cm³,less than about 0.6 g/cm³, less than about 0.5 g/cm³, less than about0.4 g/cm³, less than about 0.3 g/cm³, less than about 0.2 g/cm³, or lessthan about 0.1 g/cm³.

In some embodiments, the diameter or diagonal of the matrix can rangefrom 1 mm to 50 mm. In some embodiments, the diameter or diagonal of thematrix can range from 1 mm to 30 mm, or 5 mm to 10 mm which is smallenough to fit through an endoscopic cannula, but large enough tominimize the number of matrices needed to fill a large the bone defect(e.g., osteochondral defect). In some embodiments, at the time ofsurgery, the matrix can be soaked with an oxysterol and molded by thesurgeon to the desired shape to fit the tissue or bone defect.

In some embodiments, the porous interior can hold the oxysterol withinthe matrix and because the interior is porous, the oxysterol is evenlydistributed throughout the matrix when oxysterol is incorporated intothe matrix, as discussed herein.

In some embodiments, oxysterol will be held within the interior of thematrix and released into the environment surrounding the matrix (e.g.,bone defect, osteochondral defect, etc.) as the matrix degrades overtime.

In some embodiments, the matrix may be seeded with harvested bone cellsand/or bone tissue, such as for example, cortical bone, autogenous bone,allogenic bones and/or xenogenic bone. In some embodiments, the matrixmay be seeded with harvested cartilage cells and/or cartilage tissue(e.g., autogenous, allogenic, and/or xenogenic cartilage tissue). Forexample, before insertion into the target tissue site, the matrix can bewetted with the graft bone tissue/cells, usually with bone tissue/cellsaspirated from the patient, at a ratio of about 3:1, 2:1, 1:1, 1:3 or1:2 by volume. The bone tissue/cells are permitted to soak into thematrix provided, and the matrix may be kneaded by hand or machine,thereby obtaining a pliable and cohesive consistency that maysubsequently be packed into the bone defect. In some embodiments, thematrix provides a malleable, non-water soluble carrier that permitsaccurate placement and retention at the implantation site. In someembodiments, the harvested bone and/or cartilage cells can be mixed withthe oxysterol and seeded in the interior of the matrix.

Method of Treating

In some embodiments, the implant comprises a biodegradable polymer,porous ceramic particles and an oxysterol, such as, for example, Oxy133,to promote osteogenesis. In use, Oxy133 provides therapeutic treatmentfor bone conditions. Oxy133 facilitates bone formation, osteoblasticdifferentiation, osteomorphogenesis and/or osteoproliferation. Treatmentcan be administered to treat open fractures and fractures at high riskof non-union, and in subjects with spinal disorders. That is, Oxy133 caninduce spinal fusion and may help treat degenerative disc disease orarthritis affecting the lumbar or cervical vertebrae.

In some embodiments, provided is a method for treating a bone defectsite. In some embodiments, a compression resistant implant as describedherein is implanted at or near the bone defect to promote bone growth,the compression resistant implant comprising porous ceramic particles inan amount of about 30 wt % to about 99.5 wt % based on a total weight ofthe implant in a biodegradable polymer in an amount of about 0.1 wt % toabout 20 wt % based on the total weight of the implant, and an oxysteroldisposed in or on the compression resistant implant so as to treat thebone defect.

In some embodiments, the implant is administered by first wetting thematrix to impart malleability and moldability properties to the implant.The implant can be molded to different sizes, shapes and configurations.There are several factors that can be taken into consideration indetermining the size, shape and configuration of the implant. Forexample, both the size and shape may allow for ease in positioning theimplant at the target tissue site that is selected as the implantation.In addition, the shape and size of the system should be selected so asto minimize or prevent the implant from moving after implantation. Invarious embodiments, the implant can be shaped like a rod or a flatsurface such as a film or sheet (e.g., ribbon-like) or the like.Flexibility may be a consideration so as to facilitate placement of thedevice.

Mesenchymal stem cells treated with Oxy133 have increased osteoblastdifferentiation. Thus, in some embodiments, a matrix comprising Oxy133may be implanted into a spinal site with mesenchymal stem cells toinduce bone growth through osteoblast differentiation. Periosteum tissueis one tissue type that is involved early during normal bone fracturerepair process and can recruit various cell types (e.g., mesenchymalstem cells) and bone growth factors necessary for bone fracture repair.Thus, in some embodiments, periosteum tissue is utilized as a source ofmesenchymal stem cells and/or growth factors in a demineralized bonecomposition.

In some embodiments, an implant comprising Oxy133 may be implanted orinjected directly to a surgical site on a patient. In some embodiments,the implant is configured to release Oxy133 in the form of a depot. Invarious embodiments, a plurality of depots (e.g., pellets) can beadministered to a surgical site. In some embodiments, a plurality ofmatrices are provided (e.g., in a kit) and administered to a surgicalsite and triangulate and/or surround the site needed for bone growth. Invarious embodiments, a plurality of matrices comprise about 1, 2, 3, 4,5, 6, 7, 8, 9 or 10 depots. In some embodiments, a plasticizer is usedto lower glass translation temperature in order to affect stability ofthe implant.

Radiographic markers can be included on the implant to permit the userto position it accurately into the target site of the patient. Theseradiographic markers will also permit the user to track movement anddegradation of the implant at the site over time. In this embodiment,the user may accurately position the implant in the site using any ofthe numerous diagnostic imaging procedures. Such diagnostic imagingprocedures include, for example, X-ray imaging or fluoroscopy. Examplesof such radiographic markers include, but are not limited to, ceramics,barium, phosphate, bismuth, iodine, tantalum, tungsten, and/or metalbeads or particles. In various embodiments, the radiographic markercould be a spherical shape or a ring around the implant. The ceramic inthe composition can also be used as a radiographic marker.

In some embodiments, the implant comprising the oxysterol can beadministered to the target site by being shaped according to the needsof a medical procedure and passed through a “cannula” or “needle” thatcan be a part of a delivery device e.g., a syringe, a gun deliverydevice, or any medical device suitable for the delivery of the implantto a targeted organ or anatomic region. The cannula or needle of thedevice is designed to cause minimal physical and psychological trauma tothe patient.

Biodegradable Polymer

In some embodiments, the matrix comprises a biodegradable polymer, suchas, for example, collagen. Exemplary collagens include human ornon-human (bovine, ovine, piscine, and/or porcine), as well asrecombinant collagen or combinations thereof. Examples of suitablecollagen include, but are not limited to, human collagen type I, humancollagen type II, human collagen type III, human collagen type IV, humancollagen type V, human collagen type VI, human collagen type VII, humancollagen type VIII, human collagen type IX, human collagen type X, humancollagen type XI, human collagen type XII, human collagen type XIII,human collagen type XIV, human collagen type XV, human collagen typeXVI, human collagen type XVII, human collagen type XVIII, human collagentype XIX, human collagen type XXI, human collagen type XXII, humancollagen type XXIII, human collagen type XXIV, human collagen type XXV,human collagen type XXVI, human collagen type XXVII, and human collagentype XXVIII, or combinations thereof. Collagen further may comprisehetero- and homo-trimers of any of the above-recited collagen types. Insome embodiments, the collagen comprises hetero- or homo-trimers ofhuman collagen type I, human collagen type II, human collagen type III,or combinations thereof.

In some embodiments, the matrix comprises collagen-containingbiomaterials from the implant market which, when placed in a bonedefect, provide scaffolding around which the patient's new bone and/orcartilage will grow, gradually replacing the carrier matrix as thetarget site heals. Examples of suitable carrier matrices may include,but are not limited to, the MasterGraft® Matrix produced by MedtronicSofamor Danek, Inc., Memphis, Tenn.; MasterGraft® Putty produced byMedtronic Sofamor Danek, Inc., Memphis, Tenn.; Absorbable CollagenSponge (“ACS”) produced by Integra LifeSciences Corporation, Plainsboro,N.J.; bovine skin collagen fibers coated with hydroxyapatite, e.g.Healos®. marketed by Johnson & Johnson, USA; collagen sponges, e.g.Hemostagene® marketed by Coletica S A, France, or e.g., Helisat®marketed by Integra Life Sciences Inc., USA; and Collagraft® Bone GraftMatrix produced by Zimmer Holdings, Inc., Warsaw, Ind.

In some embodiments, the collagen contains both soluble collagen andinsoluble collagen fibers. The soluble collagen and insoluble collagenfibers can first be prepared separately, and then combined. Both thesoluble collagen and the insoluble collagen fibers can be derived from avariety of sources, including human, bovine, ovine, piscine, or porcinesources.

In certain embodiments, the matrix includes moldable compositions thatinclude the insoluble collagen fibers at a level of 0.04 g/cc to 0.1g/cc of the matrix, and soluble collagen at a level of 0.01 g/cc to 0.08g/cc of the matrix. In other embodiments, such compositions includeinsoluble collagen fibers at a level of about 0.05 to 0.08 g/cc in thematrix, and soluble collagen at a level of about 0.02 to about 0.05 g/ccin the matrix. In general, the matrix will include insoluble collagenfibers in an amount (percent by weight) that is at least equal to orgreater than the amount of soluble collagen, to contribute beneficiallyto the desired handling and implant properties of the matrix material.In some embodiments, the collagenous matrix will include insolublecollagen fibers and soluble collagen present in a weight ratio of 4:1 to1:1, more advantageously about 75:25 to about 60:40. In otherembodiments, the matrix may include the insoluble collagen fibers andsoluble collagen in a weight ratio of about 75:25 to about 65:35, and inone specific embodiment about 70:30.

In some embodiments, the matrix comprises biodegradable polymeric ornon-polymeric material. In some embodiments, the matrix may include abiodegradable biopolymer that may provide immediate release, orsustained release of the oxysterol. For example, the biodegradablepolymer comprises polyether ether ketone (PEEK). In some embodiments,the matrix may comprise one or more poly (alpha-hydroxy acids),polyglycolide (PG), polyethylene glycol (PEG) conjugates of poly(alpha-hydroxy acids), polyorthoesters (POE), polyaspirins,polyphosphagenes, collagen, hydrolyzed collagen, gelatin, hydrolyzedgelatin, fractions of hydrolyzed gelatin, elastin, starch,pre-gelatinized starch, hyaluronic acid, chitosan, alginate, albumin,fibrin, vitamin E analogs, such as alpha tocopheryl acetate, d-alphatocopheryl succinate, D,L-lactide, or L-lactide, caprolactone, dextrans,vinylpyrrolidone, polyvinyl alcohol (PVA), PVA-g-PLGA, PEGT-PBTcopolymer (polyactive), methacrylates, PEO-PPO-PAA copolymers,PLGA-PEO-PLGA, PEG-PLG, PLA-PLGA, poloxamer 407, PEG-PLGA-PEG triblockcopolymers, POE, SAIB (sucrose acetate isobutyrate), polydioxanone,methylmethacrylate (MMA), MMA and N-vinylpyyrolidone, polyamide,oxycellulose, copolymer of glycolic acid and trimethylene carbonate,polyesteramides, polyether ether ketone, polymethylmethacrylate,silicone, hyaluronic acid, chitosan, or combinations thereof.

In some embodiments, the implant may not be fully biodegradable. Forexample, the device may comprise polyurethane, polyurea,polyether(amide), PEBA, thermoplastic elastomeric olefin, copolyester,and styrenic thermoplastic elastomer, steel, aluminum, stainless steel,titanium, metal alloys with high non-ferrous metal content and a lowrelative proportion of iron, carbon device, glass device, plastics,ceramics, methacrylates, poly (N-isopropylacrylamide), PEO-PPO-PEO(pluronics) or combinations thereof. Typically, these types of matricesmay need to be removed after a certain amount of time.

In some embodiments, the implant comprises biodegradable polymerscomprising wherein the at least one biodegradable polymer comprises oneor more of poly(lactide-co-glycolide) (PLGA), polylactide (PLA),polyglycolide (PGA), D-lactide, D,L-lactide, L-lactide,D,L-lactide-co-ε-caprolactone, L-lactide-co-ε-caprolactone,D,L-lactide-co-glycolide-co-ε-caprolactone,poly(D,L-lactide-co-caprolactone), poly(L-lactide-co-caprolactone),poly(D-lactide-co-caprolactone), poly(D,L-lactide), poly(D-lactide),poly(L-lactide), poly(esteramide) or a combination thereof. In someembodiments, the oxysterol is encapsulated in a biodegradable polymer.

In some embodiments, the matrix comprises one or more polymers (e.g.,PLA, PLGA, etc.) having a MW of from about 15,000 to about 150,000 Da orfrom about 25,000 to about 100,000 Da.

In some embodiments, the implant comprises at least one biodegradablematerial in a wt % of about 99.5%, 99%, 98%, 97%, 96%, 95%, 94%, 93%,92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80%, 79%,78%, 76%, 75%, 74%, 73%, 72%, 71%, 70%, 65%, 60%, 55%, 50%, 45%, 35%,25%, 20%, 15%, 10%, or 5% based on the total weight of the matrix or theimplant. In some embodiments, the biodegradable polymer comprises arange of about 0.1% to about 20% based on the total weight of the matrixor the implant. In some embodiments, the biodegradable polymer comprisesa range of about 0.1% to about 15% based on the total weight of thematrix or the implant. In some embodiments, the biodegradable polymercomprises 14%, 13%, 12%, 11%, 9%, 8%, 7%, 6%, or 5% based on the totalweight of the matrix or the implant.

Mannitol, trehalose, dextran, mPEG and/or PEG may be used as aplasticizer for the polymer. In some embodiments, the polymer and/orplasticizer may also be coated on the implant to provide the desiredrelease profile. In some embodiments, the coating thickness may be thin,for example, from about 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50 micronsto thicker coatings 60, 65, 70, 75, 80, 85, 90, 95, 100 microns to delayrelease of the oxysterol from the implant. In some embodiments, therange of the coating on the implant ranges from about 5 microns to about250 microns or 5 microns to about 200 microns to delay release from theimplant.

Compression resistance is needed for many tissue engineeringapplications such as tibial plateau fractures, acetabular defects, longbone comminuted fractures, oral maxillofacial defects, spinal fusions,and cartilage subchondral defects. Compression resistant matrices willhelp facilitate adequate volumes of newly formed bone.

In some embodiments, the matrix is compression resistant where thematrix resists reduction in size or an increase in density when a forceis applied as compared to matrices without the ceramic particlesdisposed in it. In various embodiments, the matrix resists compressionby at 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%,75%, 80%, 85%, 90%, 95%, or more in one or all directions when a forceis applied to the matrix.

Porous Ceramic Particles

In some embodiments, the matrix comprises mineral particles, such as,for example, porous ceramic particles. In some embodiments, theparticles in the matrix comprise a resorbable ceramic, bone, syntheticdegradable polymer, hyaluronic acid, chitosan or combinations thereof.In some embodiments, the particles comprise cortical, cancellous, and/orcorticocancellous, allogenic, xenogenic or transgenic bone tissue. Thebone component can be fully mineralized or partially or fullydemineralized or combinations thereof. The bone component can consist offully mineralized or partially or fully demineralized bone.

In some embodiments, the matrix may comprise a resorbable ceramic (e.g.,hydroxyapatite, tricalcium phosphate, bioglasses, calcium sulfate, etc.)tyrosine-derived polycarbonate poly (DTE-co-DT carbonate), in which thependant group via the tyrosine—an amino acid—is either an ethyl ester(DTE) or free carboxylate (DT) or combinations thereof.

In some embodiments, the matrix may contain an inorganic material, suchas an inorganic ceramic and/or bone substitute material. Exemplaryinorganic materials or bone substitute materials include but are notlimited to aragonite, dahlite, calcite, brushite, amorphous calciumcarbonate, vaterite, weddellite, whewellite, struvite, urate,ferrihydrate, francolite, monohydrocalcite, magnetite, goethite, dentin,calcium carbonate, calcium sulfate, calcium phosphosilicate, sodiumphosphate, calcium aluminate, calcium phosphate, hydroxyapatite,alpha-tricalcium phosphate, dicalcium phosphate, β-tricalcium phosphate,tetracalcium phosphate, amorphous calcium phosphate, octacalciumphosphate, BIOGLASS™ fluoroapatite, chlorapatite, magnesium-substitutedtricalcium phosphate, carbonate hydroxyapatite, substituted forms ofhydroxyapatite (e.g., hydroxyapatite derived from bone may besubstituted with other ions such as fluoride, chloride, magnesiumsodium, potassium, etc.), or combinations or derivatives thereof.

In some embodiments, by including inorganic ceramics, such as forexample, calcium phosphate, in the matrix, this will act as a localsource of calcium and phosphate to the cells attempting to deposit newbone. The inorganic ceramic also provides compression resistance andload bearing characteristics to the matrix.

In some embodiments, the porous ceramic particles in the matrix comprisetricalcium phosphate and hydroxyapatite in a ratio of about 80:20 toabout 90:10. In some embodiments, the porous ceramic particles in thematrix comprise tricalcium phosphate and hydroxyapatite in a ratio ofabout 70:30 to about 95:5. In some embodiments, the porous ceramicparticles in the matrix comprise tricalcium phosphate and hydroxyapatitein a ratio of about 85:15.

In some embodiments, the implant can contain demineralized bone materialdisposed therein. The demineralized bone material can be comprisedemineralized bone, powder, chips, triangular prisms, spheres, cubes,cylinders, shards, fibers or other shapes having irregular or randomgeometries. These can include, for example, “substantiallydemineralized,” “partially demineralized,” or “fully demineralized”cortical and cancellous bone. These also include surfacedemineralization, where the surface of the bone construct issubstantially demineralized, partially demineralized, or fullydemineralized, yet the body of the bone construct is fully mineralized.In some embodiments, the covering may comprise some fully mineralizedbone material. The configuration of the bone material can be obtained bymilling, shaving, cutting or machining whole bone as described in forexample U.S. Pat. No. 5,899,939. The entire disclosure is hereinincorporated by reference into the present disclosure.

In some embodiments, the implant comprises elongated demineralized bonefibers having an average length to average thickness ratio or aspectratio of the fibers from about 50:1 to about 1000:1. In overallappearance the elongated demineralized bone fibers can be in the form ofthreads, narrow strips, or thin sheets. The elongated demineralized bonefibers can be substantially linear in appearance or they can be coiledto resemble springs. In some embodiments, the elongated demineralizedbone fibers are of irregular shapes including, for example, linear,serpentine or curved shapes. The elongated bone fibers can bedemineralized however some of the original mineral content may beretained when desirable for a particular embodiment.

In some embodiments, the implant comprises elongated demineralized bonefibers and chips. In some embodiments, the implant comprises fullydemineralized fibers and surface demineralized chips. In someembodiments, the ratio of fibers to chips or powders is from about 5,10, 15, 20, 25, 30, 35, 40, or 45 fibers to about 30, 35, 40, 45, 50,55, 60, 65, or 70 chips.

In some embodiments, the biocompatible material comprises demineralizedbone matrix fibers and demineralized bone matrix chips in a 30:60 ratio.In some embodiments, the biocompatible material comprises demineralizedbone matrix fibers and demineralized bone matrix chips in a ratio of25:75 to about 75:25 fibers to chips.

In some embodiments, the matrix comprises porous ceramic particles thatoffer compression resistance. In some embodiments, the particlescomprise at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%,65%, 70%, 75%, 80%, 85%, 90%, 95%, or 99.5% by weight of the matrix. Insome embodiments, the particles are predominantly any shape (e.g.,round, spherical, elongated, powders, chips, fibers, cylinders, etc.).In some embodiments, the matrix comprises porous ceramic particles in anamount of about 0.1 wt % to about 99.5 wt % of the matrix. In someembodiments, the matrix comprises porous ceramic particles in an amountof about 30 wt % to about 99.5 wt % of the matrix. In some embodiments,the matrix comprises from about 30, 31%, 32%, 33%, 34%, 35%, 36%, 37%,38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%,52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%,66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%,80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99%, or 99.5% by weight of ceramic particles inthe matrix.

In some embodiments, the porosity of the particles comprises from 0 to50%, in some embodiments, the porosity of the particles comprises 5% to25%. In some embodiments, the particles are not entangled with eachother but contact each other and portions of each particle overlap inthe matrix to provide compression resistance. In some embodiments, atleast 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or more of theparticles overlap each other in the matrix. In some embodiments, theimplant includes a high level of porosity. For example, in someembodiments, the porosity is between about 50% and about 90%, betweenabout 50% and about 95%, or between about 50% and about 98%. In someembodiments the porosity of the implant is between about 60% and about75%.

Due to porosity and overlapping particles, the implantable biocompatibleporous solid matrices such as ceramics, and more specifically thematrices having interconnected pores, are advantageous in that theyincrease the interchange surface area with the biological medium, arebioresorbable, promote the revascularization of the tissues and haveexcellent osteoconductive properties. Moreover, growth agents may bedeposited into the pores by means of precipitation. In some embodiments,the implant has compression strength of at least about 5 MPa, at leastabout 10 MPa, at least about 20 MPa, at least about 30 MPa, or at leastabout 40 MPa. In some embodiments, the implant includes a compressionstrength of about 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 16 MPa, 17MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23 MPa, 24 MPa, 25 MPa, 26MPa, 27 MPa, 28 MPa, 29 MPa, 30 MPa, 31 MPa, 32 MPa, 33 MPa, 34 MPa, 35MPa, 36 MPa, 37 MPa, 38 MPa, 39 MPa, 40 MPa, or any value therebetween.In some embodiments, the implant has a compression strength betweenabout 2 MPa and about 40 MPA, between about 10 MPa and about 30 MPa, orbetween about 15 MPa and about 25 MPa.

In some embodiments, the implant is able to resist compression in morethan one dimension or direction. In some embodiments, the implantresists compression in any dimension or direction. In some embodiments,the implant is not compressed any more than about 30% in any onedirection, any more than about 20% in any one direction, any more than10% in any one direction, or any more than 5% in any one direction.

In some embodiments, the aforementioned degree of compression resistanceof the implant is maintained for a period of at least about 30 days, atleast about 40 days, at least about 50 days, at least about 60 days, atleast about 75 days, at least about 90 days, at least about 120 days, atleast about 150 days or at least about 180 days in vivo. In someembodiments, the implant maintains the compression resistance for aperiod of about 5 days, 10 days, 15 days, 20 days, 25 days, 30 days, 35days, 40 days, 45 days, 50 days, 55 days, 60 days, 65 days, 70 days, 75days, 80 days, 85 days, 90 days, 95 days, 100 days, 105 days, 110 days,115 days, 120 days, 125 days, 130 days, 135 days, 140 days, 145 days,150 days, 155 days, 160 days, 170 days, 175 days, 180 days, or any valuetherebetween.

In some embodiments, the particles are randomly distributed throughoutthe matrix. In other embodiments, the particles are uniformly or evenlydistributed throughout the matrix. In some embodiments, the particlesmay be dispersed in the matrix using a dispersing agent. In otherembodiments, the particles may be stirred in the polymer and themechanical agitation will distribute the particles in the matrix untilthe desired distribution is reached (e.g., random or uniform).

In some embodiments, the matrix may be seeded with harvested bone cellsand/or bone tissue, such as for example, cortical bone, autogenous bone,allogenic bones and/or xenogenic bone. In some embodiments, the matrixmay be seeded with harvested cartilage cells and/or cartilage tissue(e.g., autogenous, allogenic, and/or xenogenic cartilage tissue). Forexample, before insertion into the target tissue site, the matrix can bewetted with the graft bone tissue/cells, usually with bone tissue/cellsaspirated from the patient, at a ratio of about 3:1, 2:1, 1:1, 1:3 or1:2 by volume. The bone tissue/cells are permitted to soak into thematrix provided, and the matrix may be kneaded by hand or machine,thereby obtaining a pliable and cohesive consistency that maysubsequently be packed into the bone defect. In some embodiments, thematrix provides a malleable, non-water soluble carrier that permitsaccurate placement and retention at the implantation site. In someembodiments, the harvested bone and/or cartilage cells can be mixed withthe statin and seeded in the interior of the matrix.

In some embodiments, tissue will infiltrate the matrix to a degree ofabout at least 50 percent within about 1 month to about 6 months afterimplantation of the matrix. In some embodiments, about 75 percent of thematrix will be infiltrated by tissue within about 2-3 months afterimplantation of the matrix. In some embodiments, the matrix will besubstantially, e.g., about 90 percent or more, submerged in or envelopedby tissue within about 6 months after implantation of the matrix. Insome embodiments, the matrix will be completely submerged in orenveloped by tissue within about 9-12 months after implantation.

In some embodiments, upon implantation of the matrix or components thatcontact the matrix (e.g., plugs that are separate from the matrix onimplantation), compression of the matrix is reduced or eliminated. Ifunwanted compression occurs, this causes undesirable concentrations ofthe oxysterol, such as Oxy133, to escape from the implant. This highconcentration of oxysterol may lead to local transient bone resorptionand excess osteoclast formation and bone breakdown. This may result inpoor integration of the implant with surrounding host tissue and afailed repair. Thus, by employing a compression resistant implant,unwanted leakage of the oxysterol is reduced or avoided. In someembodiments, localized release of the oxysterol may cause localirritation to the surrounding tissue. In some embodiments, the leakingof oxysterol from the implant may reduce a stable microenvironment fornew bone and/or cartilage growth. It also may cause the implant to failto retain its full efficacy over time to maximally promote bone growthat a target site.

Expandable Phase

In some embodiments, the implant may comprise a material, such as, forexample, an expandable phase, to facilitate swelling of the implant. Theexpandable phase comprises polymers that swell upon taking in fluid(e.g., saline, water, bodily fluid, etc.), and thus increase the volumeof the implant and which further holds the implant in position overtime.

In some embodiments, the expandable phase comprises a range of about0.1% to about 20% based on the total weight of the matrix or theimplant. In some embodiments, the biodegradable polymer comprises arange of about 0.1% to about 10% based on the total weight of the matrixor the implant. In some embodiments, the expandable phase comprises0.1%, 0.25%, 0.5%, 0.75%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%based on the total weight of the matrix or the implant.

In some embodiments, the expandable phase comprises polymers, monomers,starches, gums, poly(amino acids) or a combination thereof that swellupon contact with fluid (water, saline, body fluids, etc.). In variousembodiments, the amount of swelling can range from 5 to 100 percent, 5to 40 percent, or 5 to 20 percent. The time to reach maximum swellingcan be varied depending on the location and desired property of theimplant. In practice, the time to reach maximum swelling can occurwithin a period of 5 days, 3 days, 2 days or within a period of 24hours.

Suitable swellable material may include, for example, hydroxypropylcellulose, hydroxypropyl methylcellulose, hydroxyethyl methylcellulose,carboxymethylcellulose, hydroxyethylcellulose and salts thereof,Carbopol, poly(hydroxyethylmethacrylate),poly(methoxyethylmethacrylate), poly(methoxyethoxy-ethylmethacrylate),polymethylmethacrylate (PMMA), methylmethacrylate (MMA), gelatin,polyvinyl alcohols, propylene glycol, PEG 200, PEG 300, PEG 400, PEG500, PEG 550, PEG 600, PEG 700, PEG 800, PEG 900, PEG 1000, PEG 1450,PEG 3350, PEG 4500, PEG 8000 or combinations thereof. In someembodiments, the expandable phase includes gelling polymers includingbut not limited to cellulosic polymers, vinyl polymers, such aspolyvinylpyrrolidone; acrylic polymers and copolymers, such as acrylicacid polymer, methacrylic acid copolymers, ethyl acrylate-methylmethacrylate copolymers, or the like; or mixtures thereof.

A non-limiting list of swellable materials which the expandable phasemay comprise include polyvinyl alcohol (PVA), PVA modified withhydrophilic co-monomers, e.g., AMPS, PVA modified with fast crosslinkinggroups, e.g., NAAADA, PVA modified with polyvinylpyrroline (PVP),carboxymethylcellulose, polyethylene glycol (PEG), poly(vinyl ether),co-polymers of PVA and PEG, polypropylene glycol (PPG), co-polymers ofPEG and PPG, co-polymers of PVA or PPG, polyacrylonitrile,hydrocolloids, e.g. agar, alginates, collagen, elastin, chitin,chitosan, gelatin, sugar, mannitol, or the like. In various embodiments,the swellable material includes, for example,poly(N-isopropylacrylamide-co-acrylic acid)-poly(L-lactic acid) (NAL);poly(N-isopropyl acrylamide) (PNIPAM) grafted to other polymers such ascarboxymethylcellulose (CMC) copolymers or polymers including blockcopolymers and end-functionalized polymers, composites or copolymerscontaining thermo-sensitive poly(2-ethoxyethyl vinyl ether) and/orpoly(hydroxyethyl vinyl ether) and/or (EOVE200-HOVE400), whose sol-geltransition temperature is 20.5° C. The swellable material, in variousembodiments, may be used to control release of the oxysterol into thetissue and/or the synovial space.

In some embodiments, the expandable phase includes hyaluronic acid. Insome embodiments, the expandable phase includes glycosaminoglycans.Non-limiting examples of glycosaminoglycans include chondroitin sulfate,dermatan sulfate, keratin sulfate, heparin, heparan sulfate, andhyaluronan. In some embodiments, the expandable phase includes mannitol,PEG, magnesium alginate or glycerol.

The polymers may be crosslinked, lightly crosslinked hydrophilicpolymers. Although these polymers may be non-ionic, cationic,zwitterionic, or anionic, in various embodiments, the swellable polymersare cationic or anionic. In various embodiments, the swellable polymermay contain a multiplicity of acid functional groups, such as carboxylicacid groups, or salts thereof. Examples of such polymers suitable foruse herein include those which are prepared from polymerizable,acid-containing monomers, or monomers containing functional groups whichcan be converted to acid groups after polymerization. Examples of suchpolymers also include polysaccharide-based polymers such ascarboxymethyl starch and cellulose, and poly(amino acid) polymers suchas poly(aspartic acid). Some non-acid monomers may also be included,usually in minor amounts, in preparing the absorbent polymers. Suchnon-acid monomers include, for example, monomers containing thefollowing types of functional groups: carboxylate or sulfonate esters,hydroxyl groups, amide groups, amino groups, nitrile groups, quaternaryammonium salt groups, and aryl groups (e.g. phenyl groups, such as thosederived from styrene monomer). Other potential non-acid monomers includeunsaturated hydrocarbons such as ethylene, propylene, 1-butene,butadiene, or isoprene.

In some embodiments, the expandable phase comprises substances which arecapable of becoming freely permeable following hydration in aqueousfluids. Such substances include polysaccharides, such as gelatin,saccharose, sorbitol, mannanes, jaluronic acid, polyaminoacids,polyalcohols, polyglycols, or the like. In addition to the foregoing,the swellable polymer may also include additional excipients such aslubricants, flow promoting agents, plasticizers, and anti-stickingagents. For example, the expandable phase may further includepolyethylene glycol, polyvinylpyrrolidone, talc, magnesium stearate,glyceryl behenate, stearic acid, or titanium dioxide.

In various embodiments, the particle size distribution of the expandablephase material may be about 10 micrometers, 13 micrometers, 85micrometers, 100 micrometers, 151 micrometers, 200 micrometers and allsubranges therebetween. In some embodiments, at least 75% of theparticles have a size from about 10 micrometers to about 200micrometers. In some embodiments, at least 85% of the particles have asize from about 10 micrometers to about 200 micrometers. In someembodiments, at least 95% of the particles have a size from about 10micrometers to about 200 micrometers. In some embodiments, all of theparticles have a size from about 10 micrometers to about 200micrometers. In some embodiments, at least 75% of the particles have asize from about 20 micrometers to about 180 micrometers. In someembodiments, at least 85% of the particles have a size from about 20micrometers to about 180 micrometers. In some embodiments, at least 95%of the particles have a size from about 20 micrometers to about 180micrometers. In some embodiments, all of the particles have a size fromabout 20 micrometers to about 180 micrometers.

Method of Making Matrix

In some embodiments, the compression resistant implant is made by addingporous ceramic particles in an amount of about 30 wt % to about 99.5 wt% based on a total weight of the implant to a biodegradable polymer inan amount of about 0.1 wt % to about 20 wt % based on the total weightof the implant to form a mixture. In some embodiments, the mixture formsa slurry. The oxysterol is then added to the mixture to form thecompression resistant implant. In some embodiments, the matrix is dried,hardened or cured to form the implant.

In some embodiments, the compression resistant implant is made by addingan oxysterol to porous ceramic particles, the porous ceramic particlesbeing in an amount of about 30 wt % to about 99.5 wt % based on a totalweight of the implant to form a mixture. In some embodiments, themixture forms a slurry. The biodegradable polymer is then added in anamount of about 0.1 wt % to about 20 wt % based on the total weight ofthe implant to form the compression resistant implant. In someembodiments, the matrix is dried, hardened or cured to form the implant.

In some embodiments, the compression resistant matrix is made by addingan oxysterol to a biodegradable polymer, the biodegradable polymer beingin an amount of about 0.1 wt % to about 20 wt % based on the totalweight of the implant to form a mixture. In some embodiments, themixture forms a slurry. The porous ceramic particles are added to themixture to form the implant, the porous ceramic particles being in anamount of about 30 wt % to about 99.5 wt % based on a total weight ofthe implant. In some embodiments, the matrix is dried, hardened or curedto form the implant.

In various embodiments, the porous ceramic particles form a ceramicskeleton of the implant. The ceramic skeleton may contain a calciumphosphate ceramic material, such as dicalcium phosphate, tricalciumphosphate, amorphous hydroxyapatite, crystalline hydroxyapatite,coralline hydroxyapatite, hydroxyapatite e.g., ETEX CaP, silicatecontaining ceramics or a combination thereof. In some embodiments theceramic material consists of essentially or comprises fast resorbingCaPO4. It may also be possible to include some polymer (e.g., natural orsynthetic degradable polymer) in the ceramic slurry to give the skeletona degree of ductility and to render it less brittle.

In some embodiments, in manufacturing the implant, a mixture of thematrix material (e.g., collagen and oxysterol) is combined with theporous ceramic particles and a liquid to wet the material and form aputty or paste. In some embodiments, a ceramic slurry is formed bymixing the porous ceramic particles with a liquid. Any suitable liquidcan be used including, for example, aqueous preparations such as water,saline solution (e.g. physiological saline), sugar solutions, proticorganic solvents, or liquid polyhydroxy compounds such as glycerol andglycerol esters, or mixtures thereof. The liquid may, for example,constitute about 5 to about 70 weight percent of the mixed compositionprior to the molding operation. Once wetted, the implant becomesmoldable and may be shaped by a medical practitioner by hand.

The porous ceramic can be fabricated by pouring the ceramic slurry intoa porous mold made out of a material that can be dissolved away orburned out after the ceramic has set. The porous skeleton can also besintered at high temperatures, e.g., at temperatures between about 900and about 1700 degrees C. In some embodiments the skeleton is sinteredbetween about 900 degrees and about 1100 degrees C. or between about1100 and about 1300 degrees C. or between about 1300 and about 1500degrees C. or between about 1500 degrees and about 1700 degrees C. Thepolymer can then be poured over the porous ceramic.

In one embodiment of manufacture, a collagen mixture can be combinedwith porous ceramic particles, an oxysterol and a liquid, desirably withan aqueous preparation, to form a moldable cohesive mass. Excess liquidcan be removed by any suitable means, including for example by applyingthe cohesive mass to a liquid-permeable mold or form and draining awayexcess liquid.

In some embodiments, the mixture of the polymer, mineral particlesand/or oxysterol are molded to take the form of the implant. Before,during or after molding, including in some instances the application ofcompressive force to the matrix, the biodegradable polymer can besubjected to one or more additional operations such as heating,lyophilizing and/or crosslinking. In this regard, crosslinking can beused to improve the strength of the formed matrix. Alternatively, thesurface of the matrix can be crosslinked to reduce the size of the poresof the porous interior and thereby form the exterior of the matrix thatis less permeable and/or less porous than a porous interior.Crosslinking can be achieved, for example, by chemical reaction, theapplication of energy such as radiant energy (e.g. UV light or microwaveenergy), drying and/or heating and dye-mediated photo-oxidation;dehydrothermal treatment; enzymatic treatment or others.

In some embodiments, a chemical crosslinking agent is used. Examples ofsuitable cross-linking agents include those that contain bifunctional ormultifunctional reactive groups, and which react with matrix. Chemicalcrosslinking can be introduced by exposing the matrix material to achemical crosslinking agent, either by contacting it with a solution ofthe chemical crosslinking agent or by exposure to the vapors of thechemical crosslinking agent. This contacting or exposure can occurbefore, during or after a molding operation. In any event, the resultingmaterial can then be washed to remove substantially all remainingamounts of the chemical crosslinker if needed or desired for theperformance or acceptability of the final implantable matrix.

Suitable chemical crosslinking agents include mono- and dialdehydes,including glutaraldehyde and formaldehyde; polyepoxy compounds such asglycerol polyglycidyl ethers, polyethylene glycol diglycidyl ethers andother polyepoxy and diepoxy glycidyl ethers; tanning agents includingpolyvalent metallic oxides such as titanium dioxide, chromium dioxide,aluminum dioxide, zirconium salt, as well as organic tannins and otherphenolic oxides derived from plants; chemicals for esterification orcarboxyl groups followed by reaction with hydrazide to form activatedacyl azide functionalities in the collagen; dicyclohexyl carbodiimideand its derivatives as well as other heterobifunctional crosslinkingagents; hexamethylene diisocyante; and/or sugars, including glucose,will also crosslink the matrix material.

In some embodiments, the matrices are formed by mixing the oxysterolwith a polymer slurry such as collagen and pouring into a shaped mold.The composite mixture is freeze dried and possibly chemicallycrosslinked and cut to the final desired shape.

In some embodiments, the implant is formed by mixing the porous ceramicparticles, polymer and the oxysterol until a coherent mass is formed. Insome embodiments, the porous ceramic particles, polymer and theoxysterol are wetted and mixed in a mixing syringe or device.

The implant may be used to repair bone and/or cartilage at a targettissue site, e.g., one resulting from injury, defect brought aboutduring the course of surgery, infection, malignancy or developmentalmalformation. The implant can be utilized in a wide variety oforthopedic, periodontal, neurosurgical, oral and maxillofacial surgicalprocedures such as the repair of simple and/or compound fractures and/ornon-unions; external and/or internal fixations; joint reconstructionssuch as arthrodesis; general arthroplasty; cup arthroplasty of the hip;femoral and humeral head replacement; femoral head surface replacementand/or total joint replacement; repairs of the vertebral columnincluding spinal fusion and internal fixation; tumor surgery, e.g.,deficit filling; discectomy; laminectomy; excision of spinal cordtumors; anterior cervical and thoracic operations; repairs of spinalinjuries; scoliosis, lordosis and kyphosis treatments; intermaxillaryfixation of fractures; mentoplasty; temporomandibular joint replacement;alveolar ridge augmentation and reconstruction; inlay implantablematrices; implant placement and revision; sinus lifts; cosmeticprocedures; etc. Specific bones which can be repaired or replaced withthe implantable matrix herein include the ethmoid, frontal, nasal,occipital, parietal, temporal, mandible, maxilla, zygomatic, cervicalvertebra, thoracic vertebra, lumbar vertebra, sacrum, rib, sternum,clavicle, scapula, humerus, radius, ulna, carpal bones, metacarpalbones, phalanges, ilium, ischium, pubis, femur, tibia, fibula, patella,calcaneus, tarsal and/or metatarsal bones.

Application of the Oxysterol to the Matrix

In some embodiments, a therapeutic agent (oxysterol, with or without oneor more growth factors, etc.) may be disposed on or in the implant byhand, spraying, impregnating, injecting, brushing and/or pouring it toinfuse the implant.

Application of the oxysterol to the implant may occur at the time ofsurgery or by the manufacturer or in any other suitable manner. Forexample, the oxysterol may be further reconstituted using a syringe andthe syringe can be placed into the interior of the implant via insertionof a needle or cannula (piercing the matrix) and placing it into theinterior of the implant and injecting the oxysterol so it is evenlydistributed throughout the porous interior.

In some embodiments, the oxysterol may be applied to the matrix prior tocombining the materials and forming it into the final implant shape.Indeed, the oxysterol can be blended into the natural or syntheticpolymer (i.e., collagen) and poured into molds of the final shape of theimplant. Alternatively, the oxysterol, such as Oxy133, may be appliedonto and/or into the porous loaded matrix after forming it into thefinal shape by soaking, dripping, injecting, spraying, etc.

In some embodiments, the interior of the implant is loaded withoxysterol that functions as an osteoinductive factor. In someembodiments, the oxysterol can be disposed in a vial and then a surgeoncan mix a fluid with the oxysterol, which can be used to load theimplant with the oxysterol.

The amount of oxysterol, may be sufficient to cause bone and/orcartilage growth. In some embodiments, the oxysterol is Oxy133 and iscontained in one or more matrices in an amount of from 1 to 2 mg percubic centimeter of the matrix.

In some embodiments, the oxysterol is supplied in a liquid carrier(e.g., an aqueous buffered solution or organic solvent). Exemplaryaqueous buffered solutions include, but are not limited to, TE, HEPES(2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid), MES(2-morpholinoethanesulfonic acid), sodium acetate buffer, sodium citratebuffer, sodium phosphate buffer, a Tris buffer (e.g., Tris-HCL),phosphate buffered saline (PBS), sodium phosphate, potassium phosphate,sodium chloride, potassium chloride, glycerol, calcium chloride or acombination thereof. In various embodiments, the buffer concentrationcan be from about 1 mM to 100 mM. In some embodiments, the oxysterol isprovided in a vehicle (including a buffer) containing sucrose, glycine,L-glutamic acid, sodium chloride, and/or polysorbate 80. Exemplaryorganic solvents or non-aqueous solvents include DMSO, acetic acid,acetone, DME, DMF, MTBE, acetonitrile, butanol, butanone, t-butylalcohol, ethanol, polyethylene glycol, methanol, chlorobenzene,chloroform, toluene, propanol, pentane, heptane, ethanol, diethyl ether,or the like.

Additional Therapeutic Agents

In some embodiments, the implant further comprises oxysterol and one ormore additional therapeutic agents including one or more growth factors,statins, etc. Isolated osteoinductive agents that are included within amatrix are typically sterile. In a non-limiting method, sterility isreadily accomplished for example by filtration through sterilefiltration membranes (e.g., 0.2 micron membranes or filters). In oneembodiment, the matrix includes osteoinductive agents comprising one ormore members of the family of Bone Morphogenic Proteins (“BMPs”). BMPsare a class of proteins thought to have osteoinductive orgrowth-promoting activities on endogenous bone tissue, or function aspro-collagen precursors. Known members of the BMP family include, butare not limited to, BMP-1, BMP-2, BMP-3, BMP-4, BMP-5, BMP-6, BMP-7,BMP-8, BMP-9, BMP-10, BMP-11, BMP-12, BMP-13, BMP-14 (GDF-5), BMP-15,BMP-16, BMP-17, BMP-18 as well as polynucleotides or polypeptidesthereof, as well as mature polypeptides or polynucleotides encoding thesame.

BMPs utilized as osteoinductive agents comprise one or more of BMP-1;BMP-2; BMP-3; BMP-4; BMP-5; BMP-6; BMP-7; BMP-8; BMP-9; BMP-10; BMP-11;BMP-12; BMP-13; BMP-15; BMP-16; BMP-17; or BMP-18; as well as anycombination of one or more of these BMPs, including full length BMPs orfragments thereof, or combinations thereof, either as polypeptides orpolynucleotides encoding the polypeptide fragments of all of the recitedBMPs. The isolated BMP osteoinductive agents may be administered aspolynucleotides, polypeptides, full length protein or combinationsthereof.

Indeed, the preferred osteoinductive factors are the recombinant humanbone morphogenetic proteins (rhBMPs) because they are available inunlimited supply and do not transmit infectious diseases. In someembodiments, the bone morphogenetic protein is a rhBMP-2, rhBMP-4,rhBMP-7, or heterodimers thereof.

Recombinant BMP-2 can be used at a concentration of about 0.4 mg/ml toabout 10.0 mg/ml, preferably near 1.5 mg/ml. However, any bonemorphogenetic protein is contemplated including bone morphogeneticproteins designated as BMP-1 through BMP-18. BMPs are available fromWyeth, Cambridge, Mass. and the BMPs and genes encoding them may also beprepared by one skilled in the art as described in U.S. Pat. No.5,187,076 to Wozney et al.; U.S. Pat. No. 5,366,875 to Wozney et al.;U.S. Pat. No. 4,877,864 to Wang et al.; U.S. Pat. No. 5,108,922 to Wanget al.; U.S. Pat. No. 5,116,738 to Wang et al.; U.S. Pat. No. 5,013,649to Wang et al.; U.S. Pat. No. 5,106,748 to Wozney et al.; and PCT PatentNos. WO93/00432 to Wozney et al.; WO94/26893 to Celeste et al.; andWO94/26892 to Celeste et al. All osteoinductive factors are contemplatedwhether obtained as above or isolated from bone. Methods for isolatingbone morphogenetic protein from bone are described, for example, in U.S.Pat. No. 4,294,753 to Urist and Urist et al., 81 PNAS 371, 1984.

In addition to the above, the matrix may include one or more membersfrom the TGF-β superfamily. For example, the matrix may include AMH,ARTN, GDF1, GDF10, GDF11, GDF15, GDF2, GDF3, GDF3A, GDF5, GDF6, GDF7,GDF8, GDF9, GDNF, INHA, INHBA, INHBB, INHBC, INHBE, LEFTY1, LEFTY2,MSTN, NODAL, NRTN, PSPN, TGFB1, TGFB2, TGFB3, FGF, basic FGF, VEGF,insulin-like growth factor, EGF, PDGF, nerve growth factor orcombinations thereof.

The growth factors and the oxysterol of the present application may bedisposed on or in the matrix with other therapeutic agents. For example,the growth factor may be disposed on or in the carrier byelectrospraying, ionization spraying or impregnating, vibratorydispersion (including sonication), nozzle spraying,compressed-air-assisted spraying, brushing and/or pouring.

Exemplary therapeutic agents include but are not limited to IL-1inhibitors, such Kineret® (anakinra), which is a recombinant,non-glycosylated form of the human interleukin-1 receptor antagonist(IL-1Ra), or AMG 108, which is a monoclonal antibody that blocks theaction of IL-1. Therapeutic agents also include excitatory amino acidssuch as glutamate and aspartate, antagonists or inhibitors of glutamatebinding to NMDA receptors, AMPA receptors, and/or kainate receptors.Interleukin-1 receptor antagonists, thalidomide (a TNF-α releaseinhibitor), thalidomide analogues (which reduce TNF-α production bymacrophages), quinapril (an inhibitor of angiotensin II, whichupregulates TNF-α), interferons such as IL-11 (which modulate TNF-αreceptor expression), and aurin-tricarboxylic acid (which inhibitsTNF-α), may also be useful as therapeutic agents for reducinginflammation. It is further contemplated that where desirable apegylated form of the above may be used. Examples of still othertherapeutic agents include NF kappa B inhibitors such as antioxidants,such as dithiocarbamate, and other compounds, such as, for example,sulfasalazine, statins or the like.

Examples of therapeutic agents suitable for use also include, but arenot limited to, an anti-inflammatory agent, analgesic agent, orosteoinductive growth factor or a combination thereof.

Kits

The biodegradable polymer, porous ceramic particles, oxysterol anddevices to administer the implant may be sterilizable. In variousembodiments, one or more components of the matrix, and/or medical deviceto administer it may be sterilizable by radiation in a terminalsterilization step in the final packaging. Terminal sterilization of aproduct provides greater assurance of sterility than from processes suchas an aseptic process, which require individual product components to besterilized separately and the final package assembled in a sterileenvironment.

Typically, in various embodiments, gamma radiation is used in theterminal sterilization step, which involves utilizing ionizing energyfrom gamma rays that penetrates deeply in the device. Gamma rays arehighly effective in killing microorganisms, they leave no residues norhave sufficient energy to impart radioactivity to the device. Gamma rayscan be employed when the device is in the package and gammasterilization does not require high pressures or vacuum conditions,thus, package seals and other components are not stressed. In addition,gamma radiation eliminates the need for permeable packaging materials.

In some embodiments, the implantable matrix may be packaged in amoisture resistant package and then terminally sterilized by gammairradiation. In use the surgeon removes the one or all components fromthe sterile package for use.

In various embodiments, electron beam (e-beam) radiation may be used tosterilize one or more components of the matrix. E-beam radiationcomprises a form of ionizing energy, which is generally characterized bylow penetration and high-dose rates. E-beam irradiation is similar togamma processing in that it alters various chemical and molecular bondson contact, including the reproductive cells of microorganisms. Beamsproduced for e-beam sterilization are concentrated, highly-chargedstreams of electrons generated by the acceleration and conversion ofelectricity.

Other methods may also be used to sterilize the implantable matrixand/or one or more components of the matrix, including, but not limitedto, gas sterilization, such as, for example, with ethylene oxide orsteam sterilization.

In various embodiments, a kit is provided comprising the oxysterol,matrix, porous ceramic particles, and/or diluents. The kit may includeadditional parts along with the implantable matrix combined together tobe used to implant the matrix (e.g., wipes, needles, syringes, mixingsyringe or other mixing device, etc.). The kit may include the matrix ina first compartment. The second compartment may include a vial holdingthe oxysterol, diluent and any other instruments needed for thelocalized delivery. A third compartment may include gloves, drapes,wound dressings and other procedural supplies for maintaining sterilityof the implanting process, as well as an instruction booklet, which mayinclude a chart that shows how to implant the matrix afterreconstituting it. A fourth compartment may include additional needlesand/or sutures. Each tool may be separately packaged in a plastic pouchthat is radiation sterilized. A fifth compartment may include an agentfor radiographic imaging. A cover of the kit may include illustrationsof the implanting procedure and a clear plastic cover may be placed overthe compartments to maintain sterility.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to various embodimentsdescribed herein without departing from the spirit or scope of theteachings herein. Thus, it is intended that various embodiments coverother modifications and variations of various embodiments within thescope of the present teachings.

These and other aspects of the present application will be furtherappreciated upon consideration of the following Examples, which areintended to illustrate certain particular embodiments of the applicationbut are not intended to limit its scope, as defined by the claims.

EXAMPLES Example 1

A first formulation of the moldable implant was prepared having acomposition as shown in Table 1.

TABLE 1 % CMC % Collagen % Ceramic % Oxy133 4 12 80 5 4 13 54 30 2 12 805 2 13 54 30

The values listed in Table 2 refer to the composition of the dry powdercomponents of the matrix prior to being wetted with physiologicallyacceptable saline. The carboxymethylcellulose was added to impart theimplant with adhesive properties. It was found that thecarboxymethylcellulose also caused the implant to significantly expandupon wetting. In some cases, the carboxymethylcellulose expanded theimplant to twice the size of the dry compound in some dimensions. Thecollagen added to the composition was porcine fibrillar Type I collagen.The ceramic comprised beta tri-calcium phosphate and hydroxyapatite in aratio of 85:15. The ceramic particles had a particle size of about 125μm to about 750 μm. Small particles were preferred to create a largersurface area-to-volume ratio to provide for faster resorption afterimplantation in a bony defect. A relatively high amount of ceramic wasprovided to the composition to impart properties of compressionresistance. Oxy133 was added to the composition at an amount of about400 mg/cc. The Oxy133 added was in the crystalline form of amonohydrate.

Example 2

A formulation of the moldable implant was prepared having a compositionas shown in Table 2.

TABLE 2 % Collagen % Ceramic % Oxy133 8 51 41.5

The values listed in Table 2 refer to the composition of the powdercomponents of the matrix prior to being wetted with physiologicallyacceptable saline. Upon being wetted, it was found that the collagenheld the implant together with little to no crosslinking. The collagenadded to the composition was porcine fibrillar Type I collagen. Theceramic comprised beta tri-calcium phosphate and hydroxyapatite in aratio of 85:15. The ceramic particles had a particle size of about 125μm to about 750 μm. Small particles were preferred to create a largersurface area to volume ratio to provide faster resorption afterimplantation in a bony defect. A relatively high amount of ceramic wasprovided to the composition to impart properties of compressionresistance. Oxy133 was added to the composition at a level of about 400mg/cc. The Oxy133 added was in the crystalline form of a monohydrate.

Example 3

Compositions were prepared according to the specifications of Examples 1or 2 above. The compositions were wetted with sterilized water.

Example 4

Compositions were prepared according to the specifications of Examples 1or 2 above. The compositions were wetted with blood.

Example 5

Compositions were prepared according to the specifications of Examples 1or 2 above. The compositions were wetted with bone marrow aspirate.

Example 6

A dry composition of a matrix containing Oxy133, collagen, and ceramicparticles as described herein was prepared and wetted with 1.4 cc ofheparinized rabbit blood. The matrix was rolled into a ball and acylinder. It was observed that the shaped matrix showed slightfissuring, and an additional 0.3 cc of heparinized rabbit blood wasadded to the matrix. The added wetting fluid allowed the matrix to beshaped with no fissuring.

Example 7

A dry composition of a matrix containing Oxy133, collagen, ceramicparticles, and carboxymethylcellulose as described herein was prepared.The dry matrix was incrementally wetted with heparinized rabbit blood.It was found that volumes below about 1.3 cc of blood were ineffectivein adequately wetting the matrix. After 1.43 cc of blood had been added,the matrix was rolled into a cohesive ball and cylinder shapes with nofissuring. Carboxymethylcellulose was found to provide cohesiveness andadhesiveness to the matrix.

Example 8

A dry composition of a matrix containing Oxy133, collagen, and ceramicparticles as described herein was prepared and wetted with 1.46 cc ofphysiologically acceptable saline. Fresh bone graft was obtained fromthe iliac crest of rabbits. The bone chips were progressively added tothe matrix. The matrix cohesively rolled into a ball and cylinder shapeswith no fissuring when up to an amount of 2.0 cc of bone graft wasadded.

Example 9

A dry composition of a matrix containing Oxy133, collagen and ceramic asdescribed herein was prepared and wetted with sterile water to beimplanted in rat spines as shown in FIG. 6. The wetted matrix was cut inhalf with a razor blade to yield two halves. The two implants weremolded into cylindrical shapes prior to insertion and were positionedbilaterally in the posterolateral space of each test subject. Eachimplant contained 20 mg Oxy133. Radiographs were taken roughly 10minutes after the procedure, 4 weeks after the procedure, and 8 weeksafter the procedure. As shown in FIG. 6, the implants promoted bridgingbone across the transverse processes of L3-L5 at the 4-week and 8-weektimepoints. Fusion was tested at 8-week sacrifice by manual palpation.The section of the spine where the implants were located showed limitedflexibility in the manual palpation evaluation, indicating that fusionhad occurred. In this study, fusion was observed in 5/5 (100%) of therat spines receiving the described formulation.

Example 10

A dry composition of a matrix containing Oxy133, collagen and ceramic asdescribed herein was prepared and wetted with sterile water to beimplanted in rat spines as shown in FIG. 6. The wetted matrix was cut inhalf with a razor blade to yield two halves. The two implants weremolded into cylindrical shapes prior to insertion and were positionedbilaterally in the posterolateral space of each test subject. Eachimplant contained 125 mg Oxy133. Radiographs were taken roughly 10minutes after the procedure, 4 weeks after the procedure, and 8 weeksafter the procedure. As shown in FIG. 6, the implants promoted bridgingbone across the transverse processes of L3-L5 at the 4-week and 8-weektimepoints. Fusion was tested at 8-week sacrifice by manual palpation.The section of the spine where the implants were located showed limitedflexibility in the manual palpation evaluation, indicating that fusionhad occurred. In this study, fusion was observed in 5/5 (100%) of therat spines receiving the described formulation.

All patent and non-patent publications cited in this disclosure areincorporated herein in to the extent as if each of those patent andnon-patent publications was incorporated herein by reference in itsentirety. Further, even though the disclosure herein has been describedwith reference to particular examples and embodiments, it is to beunderstood that these examples and embodiments are merely illustrativeof the principles and applications of the present disclosure. It istherefore to be understood that numerous modifications may be made tothe illustrative embodiments and that other arrangements may be devisedwithout departing from the spirit and scope of the present disclosure asdefined by the following claims.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to various embodimentsdescribed herein without departing from the spirit or scope of theteachings herein. Thus, it is intended that various embodiments coverother modifications and variations of various embodiments within thescope of the present teachings.

What is claimed is:
 1. A method of treating a bone defect, the methodcomprising implanting a compression resistant implant at or near thebone defect to promote bone growth, the compression resistant implantcomprising porous ceramic particles in an amount of about 30 wt % toabout 99.5 wt % in a biodegradable polymer in an amount of about 0.1 wt% to about 20 wt % based on a total weight of the implant, and anoxysterol disposed in or on the compression resistant implant so as totreat the bone defect, wherein the oxysterol comprises(3S,5S,6S,8R,9S,10R,13S,14S,17S) 17-((S)-2-hydroxyoctan-2-yl)- 10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthrene-3,6-diol (Oxy133)in an amount of about 5.0 wt % to about 45 wt % of the implant and theOxy133 is uniformly distributed throughout the porous ceramic particles,and the Oxy133 is in monohydrate form, and the porous ceramic particlescomprise tricalcium phosphate and hydroxyapatite in a ratio of about85:15.
 2. A method according to claim 1, wherein the implant is notcompressed any more than about 20% in any one direction for a period ofat least about 30 days in vivo.
 3. A method according to claim 1,wherein (i) the porous ceramic particles are uniformly distributedthroughout the implant; (ii) the oxysterol is uniformly distributedthroughout the biodegradable polymer; and/or (iii) the oxysterol isuniformly distributed throughout the porous ceramic particles.
 4. Amethod according to claim 1, wherein the porous ceramic particles form aceramic skeleton, the skeleton having pores in the range of 1-10 mm indiameter, and a total porosity of 50-98%.
 5. A method according to claim1, wherein the porous ceramic particles form a ceramic skeleton disposedcontinuously throughout the implant, and the implant has a compressionstrength of about 2 MPa to about 40 MPa.
 6. A method according to claim1, wherein (i) the porous ceramic particles are uniformly distributedthroughout the implant; and (ii) the oxysterol is uniformly distributedthroughout the biodegradable polymer.
 7. A method according to claim 1,wherein the implant comprises autograft, allograft and/or xenograft boneparticles.
 8. A method according to claim 1, wherein the biodegradablepolymer comprises porcine-derived collagen, human-derived collagen,bovine-derived collagen, piscine-derived collagen, ovine-derivedcollagen, recombinant collagen, gelatin, or combinations thereof.
 9. Amethod according to claim 1, wherein (i) the porous ceramic particlescomprise bone powder, demineralized bone powder, porous calciumphosphate ceramics, hydroxyapatite, amorphous hydroxyapatite, tricalciumphosphate, bioactive glass or a combination thereof; (ii) the porousceramic particles include a particle size between about 125 μm and about750 μm; or (iii) the porous ceramic particles comprise tricalciumphosphate and hydroxyapatite in a ratio of about 70:30 to about 90:10.10. A method according to claim 1, wherein the implant has a compressionstrength of about 10 MPa to about 30 MPa.
 11. A method according toclaim 1, wherein the implant has a compression strength of about 15 MPato about 25 MPa.
 12. A method according to claim 1, wherein thebiodegradable polymer is in an amount of about 8.0 wt % to about 13 wt %of the implant, the porous ceramic particles are in an amount of about50 wt % to about 80 wt % of the implant, and the oxysterol is in anamount of about 5.0 wt % to about 45 wt % of the implant.
 13. A methodaccording to claim 1, wherein the compression resistant implantcomprises carboxymethyl cellulose in an amount of from about 2 wt % toabout 4 wt % based on the total weight of the implant.
 14. A methodaccording to claim 1, wherein the Oxy133 is in monohydrate form.
 15. Amethod according to claim 1, wherein the biodegradable polymer comprisesa collagen comprising insoluble collagen and soluble collagen in aweight ratio of about 75:25 to about 60:40.